8098 Maintanence Manual

 

     e      c       i      v      r      e        S

D esig n Fun Fu n ct cti io n in g M ain ten enan ance ce In spe specti ctio n

R

ZF-Servocom

Type 8090,8095,8097 and 8098

ZF Lenksystem e G m bH D -73 735 5 22 Schw Schw aebisch G m u end Teleph ephon on e (07 071 1 71) 71 ) 3 1-0 1-0 Fax (0717 07 17 1) 31 -43 439 96

8090 I02/01 e

 

Tabl ab le of o f C o n tent en ts / Safet Safety y N o te

Table of Conte onten nts Page I.

Safety n o te ...................................................................1

II.

D esig n an d fu n ctio n in g

III.

M ain ten an ce ..................................................................7

IV.

In sp ectio n .....................................................................8

V.

O il ch an g e .................................................................. 1 9

V I.

B leed in g .................................................................... 2 1

V II.

A dj d ju stin g th e h yd rau lic steerin g lim iter .......................................... 2 3

V III.

R ep air o f extern al leakag es .................................................... 2 7

IX .

R ep lacin g an d settin g th e sw itch (2 2 2 ) ......................................... 2 8

X.

Re Rep lacin g an d settin g th e p o ten tio m eter (2 3 2 ) ................................... 2 9

X I.

R em o vin g th e steerin g g ear .................................................. 3 1

X II.

In stallin g th e steerin g g ear ag ain ............................................... 3 2

X III.

Sp ecial to o ls ................................................................. 3 7

X IV.

Tro u b le sh o o tin g ............................................................. 3 9

X V.

K ey to n u m b ers in fig u res an d exp lo d ed d raw in g ................................ 4 2

........................................................2

In sp ectio n rep o rt ............................................................. 4 3

I. Safety Note Attention: Impor Im portan tantt safety afety note note for the driver driver and the workshop personnel, onnel, respe respec ctively tively If th e steer ee rin g syst ystem is in a p erf erfect w o rkin g o rd er, th e steer ee rin g eff effo rts th at th th e d river has h as to exer exe rt o n th e steeri eerin g w heel are lo w (e.g ., 3 0 N , cor corr resp esp o n d in g to app ap p ro x. 3 kg) kg ). In th e even t o f a failu re o f th e h ydr yd rau lic a as ssistan ce (fo r exam p le o w in g to lack o f o il) th e eff effo rt n eed ee d ed fo r steer ee rin g w illin creas ea se con co n sid erab erab ly (fo r in stan ce t to o 4 5 0 N , cor co rrespo n d in g to ap p ro x.4 x. 4 5 kg ). A s th is h ap p en s very rar rarel ely an d u n exp expect ected ed ly, th e d river m ay b e led to b elieve, err erro n eo u sly, th at th e steer ee rin g sys yst tem cann o t be m o ved at all any an y lo n g er. H o w ever, even in th e event of o f a failu re o f th e h ydrau ydraul lic assi ass istance, an ce, th ere ere is alw ays a ys a m ech echan ani ical calcon con n ectio n b etw etw e een en th e steeri eerin g w h eel an d th e ro ad w h eel en su rin g th at m an u al steeri eerin g at in creased steer ee rin g eff effo rts can take p lace. To avoid d am ages ag es in sid e th e steeri eerin g b o x an a n d d am ages ag es t to o th e steeri eerin g colu m n , th e steeri eerin g eff effo rt at th e steeri eerin g w heel h eelr rim m u st n o t exceed exceed 7 0 0 N (app ap p ro x.7 0 kg) kg ) w h hen en steeri eerin g m o tio n s are carr carried o u t w ith o u t hyd h ydr rau lic assi assistan ce an d w ith th e veh icle stati atio n ary ary.

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

1

 

D esi esig n and an d Fun Fun ctio n in g

II. Des Design and and Fun Func ctioning tioning 1

Design

The h ou sin g o f the ZF Servoc Servoco o m steeri eering gear h ou ses the the co nt ntr rol valve, the po w er cy cylin der an d a com p lete ete m anu an u al steeri eerin g g ear. Th The e o il flo w an and d th e p ress essu re n eed eeded ed b y th th e steeri eerin g g ear is su su p p lied b y an eng en g in e-d e-d riven p u m p . To achieve th is, th e o il is taken taken in fro m th e o il tank an k and an d fed b ack to th e said tank an k via th e p u m p and an d th e steer ee rin g g ear ea r.

 Fig ig . 1  - an d th e p isto n (B ) h ave th e fu n ctio n o f a cylin d er. Th e p isto n tran sfo rm s The ho using (A )- see F th e ro tati atio n o f th e steer eeri in g in p u t sh aft aft (C ) and an d th e w o rm (D ) in to an axialm al m o tio n w h ich it trans an sm its to th e secto secto r shaft shaft (F). By m eans o f a b allchain, the piston (B) and the w o rm (C ) are in po sitive en gag em ent. ent. A s the the w o rm ro tates ates, , th e b alls at on e en d o f th e chain are are taken u p b y a recirculati atio n tu b e and an d fed b ack to th e o th er end en d so th at an end en d less ess b all chain is fo fo rm ed. ed . The Th e teeth eeth o f th e p isto n (B ) and an d o f th e secto r sh aft aft (F)cau F)caus se th e secto r sh aft aft to ro tate ate w h en th e p isto n is d isp spl lace ced d.

Fig. 1 V alve ro to r in m id -p o sitio n

A B

H ousi ousing Pisto n

C D E F G H Q R S

V alve ro to r/in p u t sh aft aft Val Va lve sl sleeve/w o rm Tor ors sio n bar Sect Secto r sh af aft t Pressu Pressur re rel relief valve R epl ep leni en ish m ent valve O il tank V an e p u um mp Flo w lim itin g valve

R eturn lin e p ressur essure

2

Ins nst truc uct tions on D es esi ign,Func gn,Funct tioning,M aint ntena enanc nce e and Ins nspec pect tion

 

D esi esig n and an d Fun Fun ctio n in g

Th e con co n tro l valve co con n sists of o f th e valve r ro o to r (C ) w h ich is carried in a n eed le b eari earin g in th e w o rm an d is p ro vid ed w ith six con tro l g ro o ves o n th e circum cu m feren eren ce, an d o f th e valve sleeve ee ve (D ), also w ith six co nt ntr ro l gr gro o oves, oves, on the w or orm m (D ). A to rsio n b ar (E) p in n ed to th e valve r ro o to r (C ) and an d th e w or o rm (D ) keep s th e con tro lvalve in m id -p o sitio n as lo n g as n o eff effo rt is e exer xert ted o n th e steer ee rin g w h eel. A p ressur essure relief valve (G )l ) lim itin g th e m axim u m p ressu essur re w ith in th e stee steer rin g syst system m ay b e in teg rated in th e steer ee rin g g ear ea r ho u sin g . In ad d itio n , a rep len ish m e en n t valve (H ) taki ak in g in o il fro m th e retu etu rn o il lin e w hen h en a steer ee rin g m o tio n takes ak es p lace w ith o u t hydr h ydrau au lic ass assi istan ce can b e fitted to th e h o u sin g o r th e con tro l valve.

In com co m p ari arison w ith con co n stan t rati atio steer ee rin g g ear ea rs, vari variab le rati atio steer ee rin g g ear ea rs a ar re m o re d irect aro aro u n d cent cen tre th an o u tsid e th e m id -p o sitio n area, area, w h ich h as a favou avo u rab le eff effect o n th e steeri eerin g p erf erfo rm an ce as m in o r steer ee rin g cor co rrecti ectio n s o n ly, if an y, are are req u ired . A t th e sam e tim e, in th e stati atic p arki arkin g ran g e a h ig h er h ydr ydrau au lic t to o rq u e is availab le at th e secto ecto r sh aft aft as th e steer ee rin g rati atio is m o re in d irect a at t larg arg er steer ee rin g w h eel ee l tu rn in g an g les. In th e even t o f a failu re o f th e h ydr yd rau lic ass assi istan ce th e steer ee rin g eff effo rts at a t th e steer ee rin g w h eel rim are are lo w er e r in th is ran ran g e th an th ey w o u ld b e fo r a con co n stan t rati atio steer ee rin g g ear. The Th e 3 fu n ctio n ald al d raw in g s to to  Figs. 1   to   3   gi g ive a sim p lified rep resen tati atio n o f th e valve an d o f th e o il flo w . A lso , th ese fig u res g ive a cro ssss-secti ectio n al view o f th e valve in o rd er to to schem ch em ati atically rep resen t th e con n ectio n s fr fro m th e con tro l valve t to o th e cyl cylin d er cham b ers ers as w ell as th th e m o d e o f fu n ctio n in g o f th th e valve.

2

Function ioning ing

W h en a to rq u e is t tr ran sm itted fro m th e steeri eerin g in p u t sh sh aft aft to th e w or o rm o r vice-ver ce-vers sa, th e to rsio n b ar is sub jected ected to a d efo efo rm ati atio n in th e elastic a ar rea o f its len g th , caus cau sin g a to rsio n to o ccur b etw etw een ee n th e valve ro to r and an d th e valve sleeve and an d th u s t to o m o ve th e cont con tro l g ro o ves of o f th th e valve ro to r aw ay fro m th e m id -p o sitio n as com co m p ared ared to th e p o sitio n o f th e valve sleeve con co n tro l g ro o ves. ves. W h en th e steeri eerin g w heel h eel is rel released, t th h e actio n o f th e to rsio n b ar m akes th e valve retu etu rn to th e n eu tral (m id ) p o sitio n . Thr Th ro u g h th e b o re in th e h o u sin g , th e o il flo w s in to th e ann an n u lar g ro o ve o f th e valve sleeve and an d is fed to th e arcu arcuat ate e con tro l g ro o ves o f th th e in n er valve ro to r th th ro u g h th ree sym m etr etrically arr arran g ed rad ial bores. Th e p o sitio n o f th e con co n tro lg ro o ves in th e valve r ro o to r an d th e valve sleeve ee ve is su ch th at, at, in th e m id -p o sitio n o f th e valve,t ve, th e o il can flo w th ro u g h th e in let slo ts (J and an d K ) to th e axialg al g ro o ves (N and an d O ) o f th e valve sleeve, ee ve, w hi h ich are are also arcu arcuat ate. e. Fro m th ere, ere, th e o il can freel ee ly f fl lo w th ro u g h rad ial b o res t to o on e, each, each, cham ber o f the po w er cyl cylind er. A s lo n g as th th e steeri eerin g valve is in th e m id -p o sitio n , th e o il can flo w to b o th o f th e p o w er er c cyl ylin d er cham b ers ers and an d , also , flo w o ff th ro u g h th e t th h ree retu etu rn g ro o ves (P) in th e valve r ro o to r and an d , fro m th ere, ere, back to the tank. In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

3

 

D esi esig n and an d Fun Fun ctio n in g

2. 2.1 1 Forward orward steer steering ing motion motion to the right right (p (pis iston ton with right-h right-han ande ded d thread thread))

Fig. 2 V alve ro to r in o p erati eratin g p o sitio n , steeri eerin g w hee h eel l tu rn ed clo ckw ckw ise

J In let sl slo t K In let sl slo t L Retu Retu rn sl slot M

Retur Return n sl slot

N

A xialg roo ve

O

A xialg roo ve

P

Retur Return n groo ve

O p erat erati in g p ressur essure R etu etu rn p ressu essu re

W h en th e steer ee rin g w h eel ee l is tu tu rn ed to th e rig h t, th e p isto n w ill sh ift to th e rig h t (Fig. 2) . A p ressu essu re w illn o w b u ild u p in th e left eft-h an d cylin d er cham ch am b er w h ich is a fu n ctio n o f th e steeri eerin g eff effo rt req u ired . To achi ach ieve th is, th e con co n tro l g ro o ves o f th e valve ro to r are are d isp laced clo ckw ise an d th e in let slo ts (K (K ) are are o p ened en ed w id er to adm ad m it th e o il, w h ile th e in let slo ts (J) are are clo sed and an d o b stru ct th e feed in g o f o il to th e axial g ro o ves (O ) o f th e valve sleeve. eeve . The Th e o ilw ill n o w flo w th ro u g h th e in let slo ts (K ) to th e axialg al g ro o ves (N ) o f th e valve sleeve and an d , fro m th ere, ere, w ill p ass th ro u g h th e b all screw th read an d flo w to th e left eft-h an d cylin d er cham ch am b er. Th e clo sed in let s sl lo ts (J (J) p revent even t th th e o il fro m flo w in g o ff to th e tan k and an d , th u s, cause a p ressu essu re to b u ild u p . Th e o il fro m th e rig h t-h an d cylin d er cham cha m b er is d di isp laced . V ia th e o p en ed retu etu rn slo ts (M ), it flo w s to th e retu etu rn g ro o ves (P) o f th e valve ro to r. Fro m th ere, ere, it can can at any an y ti tim e flo w th ro u g h th e cen cent tral o il b o re in th e valve ro ro to r and th e w or o rm and an d o ff to th e o il tank. an k.

4

Ins nst truc uct tions on D es esi ign,Func gn,Funct tioning,M aint ntena enanc nce e and Ins nspec pect tion

 

D esi esig n and an d Fun Fun ctio n in g

2. 2.2 2

Forward orward steer steering ing motion motion to the left (piston (piston with right-h right-han ande ded d thread thread))

Fig. 3 V alve ro to r in o p erati eratin g p o sitio n Steer Steeri in g w h eel tu rn ed cou co u n ter-clo ckw ckw ise

J K L M N O

Inlet slot Inlet slot Ret Return urn slot Ret Return urn slot A xial g ro ov ove A xial g ro ov ove

P

Ret Return urn groove oove

O p erat erati in g p ressur essure R etu etu rn p ressu essu re

W h en th e steer ee rin g w h hee eel l is tu rn ed to th e left eft, th e p isto n is shi sh ifted to th e left eft (Fig. 3) . Ther Th eref efo o re, p ress essu u re b u ild -u p n o w takes ak es p lace in th e rig h t-h an d cylin d er cham cha m b er. The Th e con tro l g ro o ves o f th th e valve ro to r are are d isp laced cou n terer-clo ckw ise and an d allo w th e o il to flo w th ro u g h th e o p ened en ed in let sl slo ts (J) to th e axial g ro o ves (O ) fro m w h ere ere th ere ere is a con n ectio n to th e rig h t-h an d cylin d er cham ch am b er. Th e o il fro m th e left eft-h an d cylin d er cham ch am b er flo w s t to o th e retu etu rn g ro o ves (P) o f th e valve r ro o to r, via th e b allscrew th read ea d an d th e o p en ed retu etu rn slo ts (L), an d can th en freel ee ly flo w o ff to th e o iltan ltan k t th h ro u g h th e cent cen tral o il b o re in th e valve ro to r and th e w o or rm . In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

5

 

D esi esig n and an d Fun Fun ctio n in g

3

Fun unc ctio tion no off th the e hy hydr dra aulic ste tee eri ring ng lim limite iter r

Th e h ydr yd rau lic steer ee rin g lim iter p reve even n ts a steer ee rin g to th e lo ck sto p s at a t fu ll h ydr yd rau lic p ress essu u re. It, th u s, p ro tects th th e p u m p and an d th e steer eeri in g lin kag e and an d p reven event ts h ig h o il tem p erat eratu u res. A d o u b le-act e-acti in g steer ee rin g lim itin g valve w ith spr spri in g -lo ad ed valve p in s (T (T an d U ) is ar arran g ed in th e lo n g itu d in al d irecti ectio n in th e p isto n (B ). Th e valve p in s p ro ject over o ver th e rig h t-h an d an d th e left eft-h an d fro n t faces faces o f th th e p isto n   (Fig. 4) .

Fig. 4   Steerin g lim itin g val valve clo sed T rig h t-h an d valve p in o f steer steerin g lim itin g val valve U left eft-h an d valve p in o f steer steerin g lim itin g val valve V rig h t-h and an d cyl cylin d er c ch h am b er W left eft-h an d cylin d er ch ch am b er X rig h t-h an d ad ju stin g scr screw Y left eft-h an d ad ju stin g scr screw

O perat p erati in g p ressur essure R etu etu rn p ressu essu re

If th e p isto n is shifted to th e rig h t o r to th e left eft to w a ar rd s th th e lo ck sto p , th e valve p in s (T and an d U ) are are actu ated ated b y th th e adj ad ju stin g screw s (X and an d Y ) fastened en ed in th e h o u sin g and an d in th e cyl cylin d er co co ver. The Th e steer ee rin g lim itin g valve rem ain s clo sed u n til o n e o f th th e valve p in s h its ag ain st an ad ju stin g scr screw .

(Fig ig . 5) , th e rig h t-h an d valve p in (T) w ill h it ag ain st If fo r in stan ce th e p isto n is d isplace aced d to th e rig h t (F thilpr e adj ad juusr teinso g sth ew th(e X )o b efo efo reflothwe aw p isay en plo io ncha is mr reach eached velinpdiner(Ucha ) is sp ( laced o lp ressu ess tcr h at ilcan ato y nfroend m dcyl cy insditer cham b er (ed. W .) V toalcyl cy cham m dbier V ) and an db yfrt ohme th ere ere to th e retu etu rn lin e. W h en th e p isto n is d isp laced to th e left eft, th e sam e sequ eq u ence en ce o f o p erat erati io n s as d escr escrib ed abo ab o ve w ill take p lace b y anal an alo g y.

Fig. 5   Pisto n d isp lacem en t to th e rig h t. R ig h t-h an d valve p in o p en . O il p ressu essu re h ig h ly red red u ced ced. . R edu ed u ced o p erat erati in g p ressu ssu re

R etu etu rn p ressu essu re

A s soon soo n as th th e steeri eerin g lim itin g valve is o op p en, en , th e steer eeri in g g ear can b e tu rn ed fo rw a ar rd fu rth er at an in creased ea sed steer ee rin g eff effo rt an d w ith g reat ea tly red u ced h ydr yd rau lic ass assi istan ce u n til th e lo ck sto p is rea reach ched ed . 6

Ins nst truc uct tions on D es esi ign,Func gn,Funct tioning,M aint ntena enanc nce e and Ins nspec pect tion

 

M ain tenan en ance ce

III. Maintena Maintenanc nce e Maintenance intervals Maintenanc intervals:: W e recom m en e n d to carry o u t th e fo llo w in g w o or rk w hen h en g ener en eral al m a ai in tenan en ance ce w o or rk   ¡   is d o n e.

1

Chec Checking and and inspe inspec cting for externa externall leakp leakproofn roofnes ess/dam damages ages

C h eck th e p o w er e r-assi assisted steer ee rin g g ear ea r (w ith its b ello w s), th e p ro tecti ectin g caps cap s, th e p u m p s (en (en g in ed riven and an d g ro u n d -d riven), ven), th e valves an d th e p o w er cyl cylin d er, th e lin es a an n d th e screw ed con n ectio n s fo r leakp ro o fn ess ess an d d am ages ag es, , resp esp ectively. The Th e p isto n ro d o f th e p o w er cyl cylin d er m ay b e covered covered b y a th in o il film , b u t th ere m u st no t be any an y o il d ro p s.

Note: W h en clean ea n in g w ith a h ig h p ressu essu re clean in g u n it, m ak ake e su re n o t to to d irect th th e w ater ater jet d irect ectl ly to w a ar rd s th e seal ea lin g elem en ts o f th th e steer ee rin g syst ystem . Pen etr etrati atin g w a at ter an d im p u rities m ay cau caus se m alfu n cti ctio n s. 2

Checking ing the oil lev level

O il g rad e req u ired : p leas ea se refer efer t to o th e lu b rican ts sp speci ecificat cati io n TETE -M L 0 9 . Pri Prio r to to extr extracti actin g th e o il d ip stick, th o ro u g h ly clean ea n th e o il tan k an d its im m ed iate ate en viro n m en t t to o p ro tect th th e o il fro m b ein g so iled b y im p u rities.

Attention: To o lo w an o il level m ay a y cau se m a al lfu n ctio n s w h ich can en tail a failu re o f th e steer ee rin g syst ystem . For vehic vehicles with ZF Ser ervoc vocom RAS (Rear ear Axle Ste teer ering ing Syste tem m) C h eck th e o il level in th e straig h t ahea ah ead d d rivin g p o sitio n . If th e o illevelis abo ab o ve th th e to to p m ark, ark,t th ere ere m ay b be e a leakag eaka g e in th e m ast aster cyl cylin d er o f th e Z ZF F Servoco Servocom m RAS. C h eck th e ZF Servoco Servocom m R A S as speci spe cified in th e in stru ctio n s cover co verin g th e fu n ctio n in g , m a ai in tenan en ance ce an and d in sp ectio n o f ZF Servocom Servocom R A S steeri eerin g g ear ears s.

2.1 Oil leve level che check with the the engin ngine e stopp topped ed:: The oil m u st be to pp ed u p to the up per m ar ark k of th th e oil dipstick. 2.2 Oil leve level che check with the the engin ngine e ru runn nnin ing: g: Star Start t th th e en g in e. For vehi veh icles w ith g ro u n d -d riven em erg erg ency en cy steer eeri in g p u m p : jack u p th e d rive axle o f th th e em erg erg ency en cy steeri eerin g p u m p   ¡   and engage a g ear. W hen the eng ine is run run n ing , the oil lev evel el m u st be betw betw een the low er and th e u pp er m ark. ark. W h en th e eng en g in e is st sto p p ed, ed , th e o illevel evelm m ay r ri ise b y 1 1. ...2 cm (d epen ep end d in g o n th e size o f th e steeri eerin g system ). If th e o il level rises b y m o re th an 1 ...2 cm , th e steer ee rin g syst ystem m u st be b led. ed . ¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

7

 

In spe specti ctio n

IV. Inspec Inspectio tion n Attention: For Fo r th e sake o f in creas ea sed traff affic safety ety, w e recom eco m m en d to in sp ect th e steer ee rin g syst ystem in acco accor rd an ce w itese h thinespecti spect specti in tal erval erv o wed. to th e veh icle-s Th spinecti o nioinnterval erv s al m sayg ibven e adbjel u st e-sp p ecific in specti spectio n in terval ervals if th ere ere are are o n ly m in o r di d ifferen erences ces b etw etw een th e tw o .

1 -

Ins Inspec pection tion inte interv rva als  

to manufac anufacturing turing date date 12/93

Kind of use

Ist Inspection

IInd Inspec Inspection

In spect spe cti io n o n th e veh icle

In spect spe cti io n o n th e veh icle

IIIrd Inspec Inspection

Long -distance ance vehicles

100 000 km 6 0 0 0 0 m iles

200 000 km 1 2 0 0 0 0 m iles

300 000 km 1 8 0 0 0 0 m iles

V eh icles in lo n g an d sh o rt d istan ce u se

100 000 km 6 0 0 0 0 m iles

175 000 km 1 0 5 0 0 0 m iles

250 000 km 1 5 0 0 0 0 m iles

150 000 km 9 0 0 0 0 m iles 4 5 00 op .h rs.

200 000 km 1 2 0 0 0 0 m iles 6 0 00 op .h rs.

C o n stru ct cti io n site ve veh h icles an d veh icles in o ff-ro ad u se

80 000 km 5 0 0 0 0 m iles 2 5 00 op .h rs.

A d d itio n ally, at th e tim e o f th e IIIrd in spe spect ctio n , an in sp ect ecti io n o f th e m echan ech an ical calt tran sm issi ssio n elem en ts o f th th e ZF Servoco Servocom m steeri eerin g g ear is req requ u ired. ed . To d o so , d ism an tle th e steer ee rin g b o x an d carr carry o u t a visu al in sp ect ecti io n an d crack test, respect espe ctively, o f al a ll tran sm issi ssio n elem en ts (see R ep air In stru cti ctio n s).

-   from manufa anufac ctu turin ring g date date 1/94

Kind of of use

8

Ist. In Inspection

Further Inspec Inspections

In spect spe cti io n o n th e veh icle

In spect spe cti io n o n th e veh icle

C o n stru ct cti io n site ve veh h icles V eh icles in sho sho rt-d istan ce u se V eh icles w ith extr extrem e lo ad s

200 000 km 1 2 0 0 0 0 m iles 6 0 00 op .h rs.

ev ever ery 200 00 0 km 1 2 0 0 0 0 m iles 6 0 00 op .h rs.

Lon Lo n g -d istan ce veh icles Buses

3500 0 0 0000 0 0 mkm iles

aft after a fu rth,ea. er 250 000 km 1 5 0 0 0 0 m iles

Ins nst truc uct tions on D es esi ign,Func gn,Funct tioning,M aint ntena enanc nce e and Ins nspec pect tion

 

In spe specti ctio n

2 Carr Carrying ying out a visua visuall inspe inspec ction 2.1 Chec heck the the fit of the the mount ountin ing g sc scre rews ws R e-t e-tig h ten th e screw s of o f th e com p lete ete steer ee rin g g ear (steer ee rin g col co lu m n s, b evel b o x,s x, steer ee rin g b o x,d x, d rag lin ks and an d p o w er cyl cylin d er) er) and an d o f th e steer eeri in g g ear m o u n tin g elem ent en ts app ap p lyin g th e tig h ten in g to rq u e sp ecified b y th e vehi veh icle m a an n u fact actu u rer. C h eck w het h eth h er th e lo ckin g p late ate an d th e sp lit pi p in are are still p erfectl ectly secur secu red . B y tu tu rn in g th e steeri eerin g w heel h eel to eith er sid e o r b y ap a p p lyin g a lo ad to it, app ap p raise w h het eth h er th e fit o f th e d ro p arm arm o n th e secto r sh sh aft aft s ser err rati atio n is still tig h t. 2. 2.2 2

Chec Checking the straight traight ahead ahead driving driving position of steering teering gear gear and vehic vehicle le

Attention: Stee Steer rin g g ear ea rs fi fitted w ith an au to m ati atically ad ju stin g steer ee rin g lim iter m u st n o t b e tu rn ed to th e fin al p o sitio n s if th e steer ee rin g lin kag ka g e h ad b een ee n rem o ved p revio u sly. S   V eh icles w ith sin g le-w e-w h eel ee l su sp en sio n : Place th e w h eel ee ls o f th th e steer ee red axle o n sw ivel p lates. ates. S   V eh icles w ith a ri rig id axle: Jack u p th e steer ee red axle   ¡

S   M o ve th th e steeri eerin g g ear to m id -p o sitio n b y ro ro tati atin g it h alf th e to tal n u m b er o f st steer eeri in g w h heel eel tu rn s. Then Th en, , m o ve it fu rth er un u n til th e m arks arks  (see Fig. 6)  co in cid e.

Fig . 6 .

m ark h o u sin g

m ark

p ro tectin g cap

p ro tectin g cap

stee eer rin g in p u t sha shaf ft

m ark

 

stee eer rin g d ro p arm

m ar ark k sect ecto o r shaft

The Th e steered eered w h eels m u st n o w b e in th e straig h t ahead ah ead d rivin g p o sitio n (b y ap p lyin g a g radu ad u ated ated ru ler ag agai ain st b o th fro n t an and d b o th rear w h eels, and an d takin g th e to e-i e-in in to acc acco o u n t, check th is app ap p ro xim atively). C o rrecti ectio n s can b e m ad e b y screw in g th e b all jo in t on th e d rag lin k fu rth er in o r ou t.

Attention: If th e steer ee rin g w h eel ee l p o sitio n is no n o t cor corr rect an d /o r if a len g th cor corr recti ectio n o f th e steer ee rin g lin kag e tu rn s o u t to to b e n ecessar ecessary y, it m ay w ell b e th at t th h is n ecessi ecessity o rig in ates ates in a p reced in g accid en t-like even t. W e, th th eref erefo o re, recom eco m m en d to in sp ect w h eth eth er t th h e sect ecto o r sha shaf ft (3 0 ) ser serr rati atio n is tw isted (to d o so , extr ext ract th th e d ro p arm arm ), w h eth eth er th th e in p u t sha shaf ft is in stalled in a tw isted p o sitio n an d w h eth eth er som e o r alltr ltran sm issio n elem en ts are are b en t o r h ave cracks.In ad d itio n , m eas ea su re th e p lay as a s sp ecified in p ara. ara. 5. 5.8. 8. D ef efor orm m ed com po nen ts m ay n ot be b e re-ben t to shap e bu t m u st be replac aced. ed. ¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

9

 

In spe specti ctio n

Fo For r ve ver rsio n s w ith an au to m atical cally ad ju stin g h ydr yd rau lic steerin g lim iter: If req u ired , b u ild in n ew screw s (2 0 an d 1 2 8 ) an d read ju st th e steer ee rin g lim iter - p leas ea se r ref efer er to C h ap ter V II.

2.3

Chec hecking king the play play betwee between n the piston and and the the sector s sha haft ft (high (high spo spott settin setting) g) in mid-position

S   d Rr oag tate atelinth tkh efro stmeeri eerth ineg dgrear tom t.h e straig h t ah ead ea d d rivin g p o sitio n (cf. p ara. ara. 2 .2 ) an d rem ove o ve th th e o p arm ar S   U sin g to o l [5 ], m easu e asur re th th e in crease ea se in frictio n al to rq u e o ccu ccur rrin g w hen h en th e stee steer rin g is ro tated ated acro acr o ss th th e h ig h spo t area area (ap p ro x. 1 /2 tu rn to th e rig h t/left eft acro ss th e m id -p o sitio n ).

R eq u ired in crease ea se in fricti ctio n al to rq u e: N ew com pone ponents: Ty Type 809 8090: 0:

i- variable i- const onstant Typ e 8 09 09 5 : i - variab le i- const onstant Types 809 7/809 8: i - variable i- const onstant

U sed com po p o n ent en ts:

20...100 20...80 2 0. 0...1 20 20 20...100 20.. 20...160 20...130

N cm N cm N cm N cm N cm N cm

In creases in frictio n al to rq u e o f less th an 2 0 N cm are are p erm erm issib le A freed o m fro m p lay in th e straig h t ah ahead ead d rivin g p o sitio n m u st be guaranteed.

A n adj ad ju stm en e n t o f th e h ig h sp o t can o n ly be carried o u t w ith th e steeri eerin g g ear d isass assem b led fro m th e ve veh h icle (ZF Service C en tres).

2.4

Chec hecking king the the ste teer ering ing ang angle le

Note: Stee Steer rin g g ear ea rs w ith an au to m ati atically ad ju stin g h ydr yd rau lic steer ee rin g lim iter m ay o n ly b e ro tated ated to th e en d p o sitio n s, w ith th e stee steer rin g lin kag ka g e r rem em o ved ved, , if a fr fresh ad ju stm en t o f th e lim iter u sin g n ew scr screw s (2 0 an and d 1 2 8 ) takes p lace aft afterw erw ar ard d s; if requ eq u ired, ed , rem o ve t th h e screw s ( (2 2 0 and an d 1 2 8 ) and an d fit a p lu g fo r th is check ch eck. . Fit t th h e d rag lin k p ro visio n ally. R o tate ate th e steer eeri in g g ear ea r to th e left eft u un n til th e sto p is reach ea ched ed . R em o ve th e d rag lin k. G o o n tu rn in g th e steeri eerin g w h eel ee l to see w h eth eth er th ere ere is still a steer ee rin g reser eserve ve availab le. R ep eat th e m easur easu rin g to th e rig h t, to o . Th ere ere m u st b e a steeri eerin g reserve a avai vailab le at eith er sid e. If th is is n o t so , th e lo ck sto p screw s m u st b e rea read d ju sted . Pu t th e d rag lin k in to p lace ag a g ain an d tig h ten it¡   .

2.5

Chec hecking king the play play of th the e input input sha shaft ft bea bearin ring g in the ste teer ering ing colu colum mn

B y m o vin g (sh akin g ) th e steeri eerin g w h heel eel sid ew ar a rd to and an d fro , check w het h eth h er th ere ere is an y p lay. ay. If so , rep lace o r rep air th e steer ee rin g col co lu m n /th e b ear ea rin g .

2.6

Chec hecking king the the unive univers rsal joint, joint, the the te teles lescopic opic shaft haft and and the beve bevell box for angu angular lar play or stiff opera operation tion

If p lay (can b e id en tified b y t th h e n o ticea ceab b le ratt attlin g n o ise o ccur ccu rrin g w h en th e steer ee rin g w h eel ee l is tu rn ed to an d fro ) o r st stiff op o p erat erati io n are are asc ascer ert tain ed , rep lace th e d efect efecti ive com co m p o n en ts.

¡   see ve veh h icle m an an u factu ctu rer’ s in stru cti ctio n s 10

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In spe specti ctio n

3

Checkin ing g for le lea akage

S   Star Start t th e en g in e. S   C h eck w het he th er allscrew ed con co n n ecti ectio n s, alllin es an d al a llsealin g e el lem en e n ts o f th e com p lete ete st steer ee rin g sys yst tem (b evelb evel b o x, steeri eerin g b o x, p u m p and an d p o w er c cyl ylin d er) er) are leakpr eakp ro o f. S

  C h eck all h o ses an d lin es, th e p ro tectin g caps and an d th e b ello w s fo fo r po ssib le traces of o f chafi chafin g an d em b rittlem en t crack cracks. s.

Attention: W h en you repl ep lace h o se lin es o r p art arts w ith visib le extern ern ald al d am ages ag es su ch as fo r in stance an ce cracks acks, , o n ly u se p ressu essu re-t e-tested p art arts a an n d spa spar re p art arts r rel eleased ea sed b y the vehi veh icle m an a n u factu actu rer. Sw itch th e en g in e o ff.

4

Checkin king th the belt te tensio ion n of of the the pump dr driv ive e

C h eck th e tens en sio n o f th e d rive b elt ¡   . Even at m axim u m p u m p p ress essu u re, th e d rive b elt m u st tran sm it th e p o w er e r w ith o u t any an y slip .

5

Chec hecking king the the hydr hydrau aulic lic func functioni tioning ng of the the pum pump and and of the the stee teering ring gear gear

5.1

In Ins sta talling lling the the ZF Ser ervot votes est power power ste steer ering ing tes teste ter r

For Fo r th e im p lem en tati atio n o f th e p ress essu u re an d leak eakag ag e o iltest ltests d escr escrib ed b elo w , it is n ecessar ecessary y to d istin g u ish 2 kin d s (var (vari ian ts ➲   and   ➳) o f st steer ee rin g syst system s.

Variant   ➲ valve arra arrang nged ed in the pum pump or in the pres pressure ure line Stee Steer rin g syst system s w ith a  pressure relief valve betwe be twee en the the pump and and the the ZF Serv rvot ote est power power steer teerin ing g tes tester ter   (Fig. 7) . This m eans that that pr pres essu re relief tak takes es p lace ah ead ea d o f th th e b u ilt-in tester. O n steer ee rin g sys system s o f th th is typ type, e, th e n am ep late ate o f th e p u m p o r o f th e p ressu essu re rel relief valve w illin d icat cate e th th e m axim u m p ressu essu re (1 3 0 b ar, fo r exam p le). e).

Pressu ssur re lin e

Fig . 7 

R etur eturn lin e

¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

11

 

In spe specti ctio n

Variant   ➳ Steerin g syst system s w ith a   pr pre essur ure e re relie lieff va valve arr rran ange ged d in the the stee teering ring gea gear or in the the pre pressure ure line betwe between en th the e ZF Ser ervot votes est power power ste teer ering ing te tes ste ter r and and th the e ste teer ering ing gear gear (Fig  (Fig . 8). O n steer ee rin g syst ystem s o f th th is t typ ype, e, th e n am ep late ate o f t th h e steeri eerin g g ear o r of of t th h e p ressu essu re relief valve w ill in d icate cate th e m axim u m p ressu essu re (1 3 0 b ar, fo r exam p le). e).

Fig . 8

Pressu ssur re lin e

R etu rn lin e Fit t th h e ZF Ser Se rvot vo test po p o w er steer ee rin g tester to var vari ian ts   ➲   or b e seen fro m th e d river’ s seat sea t.

➳

  in su ch a w ay th at th e readi ead in g s can

C h eck th e o il level and an d b leed th e steer eeri in g syst ystem . Test con d itio n s: o il tem p erat eratu u re 5 0 o C

5.2 Chec hecking king the the maxim aximum um pre pressure ure of the the ZF pum pump O n th e n am epl ep late ate o f th e steeri eerin g g ear ear/ /th e p u m p o r o f th e sep arat aratel ely arr arrang an g ed p ress essu u re relief valve, read ea d th e m axim u m p erm erm issib le p ressu essu re. Star Start t th e en g in e. Set th th e p ressu essu re relief o f th th e ZF Ser Servot votest est po w e er r steeri eerin g test ester to a valu e exc excl lu d in g any an y d am ages ag es to th e steer ee rin g syst system in th e tests descr d escrib ed b elo w .

ahead ad of  t 5 .2 .1 For Fo r steer ee rin g syst system s w ith p ressu essur re relief ahe  th h e tester: Variant   ➲ H ave th e eng en g in e ru n at id lin g sp eed . C lo se th e sh u t-o ff valve o f th e ZF Servot Servotes est t p o w er steer eeri in g tester and an d read th e m axim u m p ressu essu re at th e tester.

Attention: A d m it m axi a xim u m p res ess su re fo r a sh o rt tim e o n ly (1 0 secon d s m axim u m ) to avoid an exces excess sive h eat eating -up o f the inn er part parts o f th e pu m p and , in co nsequence, nsequ ence, a p rem at atur ure e w ear of o f these part parts. O pen p en th e sh u t-o ff valve agai ag ain . Sp ecified valu e: m axim u m p ressu essu re (n am ep late) ate) 10 % If th th e sp ecified valu e is n o t att attain ed , rep lace o r rep air t th he pum p.

12

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In spe specti ctio n

5 .2 .2 For Fo r steer ee rin g syst system s w ith p ressu essur re relief aft of  th  th e tester: Variant   ➳

Attention: If th e p o w er steer ee rin g test ester er is in stalled to vari varian t ➳, m ake ak e a ab b solu tely s su u re tha that t d u rin g th e en e n tire p eri erio d o f pres press su re test estin g th e eng en g in e is r ru u n n in g at id lin g sp eed , o n ly. A n in crease in eng en g in e sp eed w ou o u ld en taip. lan la n im m ed iate ate an d shar sha rp rise in o ilp ress essu u re w h ich cou co u ld cau cause se a d am ag e to th e p ressu essu re lin e/t e/th e pum H ave th e en g in e ru n at id lin g sp eed . W h ile w at atchi chin g th e p ressu essu re g aug au g e, slo w ly clo se th e sh u t-o ff valve o f th e p o w er steer ee rin g tester u n til th e m axim u m p ressu essu re in d icated cated is attain ed . D o n o t clo se th th e valve a an n y fu fu rth er. A d m it m a axi xim u m p ress essu re fo r a sh o rt tim e o n ly (1 0 secon eco n d s m axim u m ) to avoid an excess exces sive h eati eatin g o f th e in n er p par art ts o f th e p u m p . H ave th e sh u t-o ff valve retu etu rn to its in itial p o sitio n . If m a axi xim u m p ressu essu re is n o t reach ea ched ed d u rin g th is m easu easu rin g , th e p u m p m u st be repl ep laced o r repai ep aired. ed .

5.3 Checkin king th the flow flow rate rate of th the ZF pump: Note: Speci Sp ecified valu es fo fo r flo w rate, ate, test est p ress essu re and an d test est sp eed : see tabl ab le b elo w . D esig n ati atio n s an d o p eraeratio n o f th e ZF Servot Servotest est p o w er steer ee rin g tester: er: p lease refer efer to th e sep arat arate e o p erat erati in g in stru ctio n s f fo or th e ZF Ser Se rvot vo test po w er steeri eerin g tester 5 .. .

S   Chec Checking the controlled ontrolled flow rate rate R aise th e eng en g in e sp eed u n til th e flo w rate ate o f th e p u m p rem ain s co con n stant an t des de sp ite a fu rth er in crease in sp eed ee d (ap p ro x.1 ,3 0 0 r.p .m .). Th e p u m p is n o w in th e f fl lo w sett ettin g ran g e. Sp ecified valu e: see sp are are p arts list. S   Chec hecking king th the e minimum flow rate rate A t en g in e id lin g sp eed , p ro g ressi essively clo se th e sh u t-o ff valve u n til th e test p ressu essu re sp ecified fo r th e p u m p type in q u est estio n is b u ilt u p . R ead th e fl flo w rate. ate.T Take th e cor co rrecten ect eng g in e speed spe ed/ /p u m p sp eed rati atio in to accou acco u n t. Pum p type

Testspe tspee ed

Testp Test p ressu essur re

M in im u m flo w rate ate

[r.p .m .]

[b ar]

[dm   3/m in ]

7672 7673 7674 7675 7677

500 500 500 500 500

50 50 50 50 50

5 .0 6 .6 7 .8 8 .7 12

7683 7684 7685 7686 7687 8601 8604

500 500 500 500 500 1000 350

50 50 50 50 50 120 50

5 .0 6 .1 7 .0 9 .6 1 0 .8 2 .0 4 .0

8605 8607

350 350

50 50

5 .0 5 .0

G raph raph s see see next page. In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

13

 

In spe specti ctio n

      n         i       m          /

        3

      m         d       e        t       a       r       w       o         l         F

Pum Pu m p sp eed r.p .m . M in im u m valu es

      n         i       m          /

        3

      m         d       e        t       a       r       w       o         l         F

M in im u m valu es

14

Pum Pu m p sp eed r.p .m .

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In spe specti ctio n 5.4 Chec hecking king the the hydr hydrau aulic lic ste teer ering ing limiter iter 5. 5.4. 4.1 1 Manua Manually lly adjus adjustab table le hydra hydraulic ulic steering teering limiter limiter S   V eh icles w ith a rig id axle: jack u p th e steer ee red axle   ¡ S   V eh icles w ith sin g le-w e-w h eel ee l suspen susp en sio n : Place th e w h eel ee ls o f t th h e steer ee red axle o n sw ivel p lates. ates.

S   Turn Turn th th e st steeri eerin g w hee h eelcl lclo ckw ise.W e. W h en th e axle st sto p o r th e lo ck s st to p is reache ea ched d ,g o o n t tu u rn in g th e steeri eerin g w h eel fo r a sh o rt tim e (5 secon d s m axim u m ) to o vercom e th e retu etu rn fo rce o f th e steeri eerin g valve an d reach ea ch a p o sitive sto p . Th is req req u ires a p eri erip h eral eral fo rce o f app ap p ro x. 1 0 0 ...2 0 0 N at th th e steeri eerin g w h eel. In th is po p o sitio n , read th e o il p ress essu u re at t th h e p ress essu u re g au g e:

Speci Sp ecified valu es: es: St S teeri eerin g syst ystem s

u p to 1 6 d m   3 /m in :40 :4 0 ...5 0 b ar  3

up to 20 dm /m in :50 :5 0 ...6 0 b ar above 20 dm   3 /m in :7 0 ...8 0 b ar

R ep eat ea t th is testf est fo r th e o th er d irecti ectio n o f ro tati atio n . Steer Steeri in g lim iter ad ju stm en t: p leas ea se refer efer to C h ap ter V II.

5.4.2 Automatic Automatically ally adjusting adjusting hydraulic hydraulic steering teering limiter Im p lem en t th e test as desc d escr rib ed in p ara. ara. 5 .4 .1 . If th er ere e is no m o re sp ace left eft at th e lo ck sto p com p o n ent en ts or o r if th e o il p ress essu re d o es n no o t d ro p to th e speci spe cified valu e, fit n ew scr screw s (2 0 ) an d (1 2 8 ) respect esp ecti ively a an n d re-ad e-ad ju st th e steer ee rin g lim iter in accor acco rd an ce w ith C h ap ter V II..

Sp ecified valu es: Stee Steer rin g syst ystem s u p to 1 6 d m   3 /m in : 4 0 ...5 0 b ar up to 20 dm   3 /m in : 5 0 ...6 0 b ar above 20 dm   3 /m in : 7 0 ...8 0 b ar

If th er ere e is to o m u ch sp ace avai a vailabl ab le at th e lo ck sto p com p o n ent en ts and an d if th e o ilp ress essu re d o es n o t d ro p to th e speci specified valu e, re-adj e-ad ju st th e steer ee rin g lim iter as speci specified in C h ap ter V II..

R ep eat ea t th e ab o ve test fo r th e o th er di d irecti ectio n o f ro tati atio n .

¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

15

 

In spe specti ctio n

5.5 Chec hecking king the the maximum pre pressure ure of  the steering teering gear gear Betw een the lock stop s, insert to ol [3] or Betw app rox.15 ox. 15 m m thick th rustpad ust pad s (Fig. 9)  ensurin g th at th e steer ee rin g m o tio n is sto p p ed 1 /2 to 3 /4e s teeri eer tu tuernrestr b efo ef oiroen roeachi threaxl st o p /ilnogck wstheel o p . Th est ricti ct f th en gsteer ee ing m ot oti ion m ust take plac ace e at to ol [3 ] or at th e said thr hrus ust t pad s and m u st no t be do ne by the p isto n w ith in th e p o w er e r st steer ee rin g g ear ea r.

Fig . 9

Attention: To o ls u n d er pr p res ess su re m ay b e p ress essed o u t - avo avo id any an y d irect v vi isu al con cont tact w ith th e to o l. D ang an g er of of accid ent en ts b y sq u eezin g . U se th e sp ecial to o l sp ecified b y th e veh vehi icle m an u fact actu u rer f fo o r th e axle vers versio n in q u estio n .

A t an en eng gef infeo ritd lof in g10 eed ro tNate atat et th htheest eer ininggwwheel hh eelt h e st an d gmouomn pturess rnsiunrge.fo r abo ab o u t 5 secon d s at 1s 0p0eed, ...2 , 00 seeri teer eeri heel eelt.o Rtead tohpe and m axi es R ep eat ea t t th h is test in th e o p p o site d irecti ectio n o f ro tati atio n . C au se o f in su fficien t m axim u m p ressu essu re:

S   Pressu Pressur re relief valve in th e steer ee rin g g ear ea r (o r sep separat aratel ely a ar rran g ed valve) d efecti efective S   To o m uch u ch leakag eaka g e oi o il in t th he s st teer eeri in g g ear

5.6 Checking king the the lea leakage kage oil

Note: D esig n ati atio n s an d o p erat erati io n o f th e Z ZF F Ser Servo vot test est5 5 ... p o w er e r steer ee rin g tester - p lease r ref efer er to th e sep separ arat ate e o p erati eratin g in stru ct cti io n s

5.6.1 Fo For r stee eer rin g syst system s w ith p ressur essu re relief ahe ahead ad of  t  th h e tester: variant   ➲ In ser ert t to o l [3 ] o r th ru st pad s of o f 15 m m th ickness betw betw een th e lo ck sto p com p o n ent en ts.

Attention: To o ls u n d er pr p res ess su re m ay b e p ress essed o u t - avo avo id any an y d irect v vi isu al con cont tact w ith th e to o l. D ang an g er of of accid ent en ts b y sq u eezin g . U se th e sp ecial to o l sp ecified b y th e veh vehi icle m an u fact actu u rer f fo o r th e axle vers versio n in q u estio n . A t eng in e id lin g sp eed , ro tate ate th e steeri eerin g g ear to th e lo ck sto p and an d p u ll at th e steeri eerin g w heel h eel fo r 5 secon eco n d s m axim u m w ith an eff effo rt o f ap p ro x.1 0 0 ...2 0 0 N to h ave th th e steer ee rin g valve clo se com co m p letel etely. R ead th e leakag eak age e rate ate and an d release th e steeri eerin g w h eel. R ep eat ea t t th h e test in th e o p p o site d irecti ectio n o f ro ro tati atio n . 16

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In spe specti ctio n

M ax. ax. perm . leaka eakage ge rates: es:Type 8090: Type 8 09 5. 5.. ..80 98 :

2.0 dm   3 /m in 2. 2.5 5 d m   3 /m in

C arr arryin g o u t th e leakag eaka g e o il test est at redu ed u ced flo w rate: ate: A d ju st th e ZF Ser S ervot votest est 5 ... p o w er steeri eerin g test ester to a flo w rate ate th at is 0 0. .5 d m   3 /m in h ig h er th an th e m axi a xim u m p erm erm issi ssib le leaka ea kag g e o il rate. ate. R epeat ep eat th e leakag eaka g e test est as d escr escrib ed abo ab o ve.T ve.Th h e leakag eaka g e o ilvalu e m easured easured in th e repet ep eti itio n tes est t m u st n o t exceed exceed th e valu e m easured easured p revio u sly. Pos Po ssib le causes o f to o h ig h a leakag eaka g e rate: ate:

S   p ressur essure relief or o r rep len ishm shm e en n t valve d efect efecti ive. S   steer ee rin g lim itati atio n valve o p en s t to o o ear ea rly - fo r adj ad ju stm en t pl p lease ea se refer efer to to C h ap ter V II. S   seals in th e steer ee rin g g ear ea r d efective.

5.6.2  Fo  For r stee steer rin g syst system s w ith steer ee rin g lim iter aft of  th  th e p o w e er r st steer ee rin g tester: er: variant   ➳ Th e shu sh u t-o ff valve (4 ) m u stb st b e clo sed com co m p letel etely an d th e th th ro ttle val va lve (5 ) m u stb stb e clo sed p ro g ressi essively u n til a p ress essu re is achieved th at is 3 30 0 b ar lo w er th an m axi a xim u m p ress essu re. R e-o e-o p en th e sh u t-o ff valve (4 ). In ser ert t to o l [3 ] o r th ru st pad s w ith a th ickness of 15 m m b etw etw een th e lo ck sto p com p o n ent en ts.

Attention: To o ls u n d er pr p res ess su re m ay b e p ress essed o u t - avo avo id any an y d irect v vi isu al con cont tact w ith th e to o l. D ang an g er of of accid ent en ts b y sq u eezin g . U se th e sp ecial th ru st pad p ad sp ecified b y th e vehi veh icle m an u fact actu u rer fo fo r th e axle vers versio n in q u estio n . R o tat ate e th e steeri eerin g g ear fo rw ard ard to th e sto p and an d p u ll at th e steeri eerin g w h eelf eel fo r 5 secon d s m axi a xim u m w ith an eff effo rt app ap p ro x. 1 0 0 ...2 0 0 N to h ave th e steeri eerin g valve clo se com p letel etely. R ead th e leakag eak age e rate ate and an d release th e steeri eerin g w h eel. R ep eat ea t t th h e test in th e o p p o site d irecti ectio n o f ro ro tati atio n .

5.7

Chec hecking king the the re retu turn rn to to neut neutra rall of the the valve valve

B y tu tu rn in g th e steer ee rin g w h eel ee l, clo se th e steer ee rin g valve, th u s caus cau sin g m axim u m p ressu essu re to b u ild u p . Th en tu rn th e steeri eerin g w h eel b ack u n til id le p ress essu u re is availab le. N ext, ext, raise th e p ressu essu re to id le p ress essu re + 1 0 b ar. R eleas ea se th th e steer ee rin g w h eela ee lan n d o b serve erve t th h e p ressu essu re. W ith in 1 secon eco n d , th e p ressu essu re m u st d ro p to id le p ress essu u re (at m axi a xim u m 0 .5 b ar hi h ig h er) er).

Exam p le: Idle pressure M ax. perm . value

4.0 bar bar 4.5 bar

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

17

 

In spe specti ctio n 5.8 Chec hecking king the the ste teer ering ing play play

Spreaders

Prer Prereq eq u isite fo r th th e test d escrib ed b elo w : Th e tran sm issio n p art arts b etw etw een ee n th e steer ee rin g w heel and the road w heel m us u st be free from p lay.

S   V ersi ersio n s w ith leaf ea f spr sprin g : Lo ck the LH fron t w heel (the RH fro nt w heel if th e vehi veh icle is RH R H steer ee red ) in th e straig h t ah ead ea d d rivin g p o sitio n b y fittin g tw o sp read ers ers b etw een th e w heel hee l rim (fro n t and rear) ear) and th e fro n t spr sp rin g   (Fig. 10) .

Attention: D o n o t exert any an y p ress essu res in exc exces ess s o f th o se m enti entioned below on the tools and on the w heel rim in o rd er t to o avoid dam ag es to th e w h eel rim .

Fig. 10

S   V ersi ersio n s w ith sin g le-w e-w h eel ee l su sp en sio n : Lock Lo ck t th h e LH fro n t w h eel( eel (th e R H fro n t w h eeli ee lif th e veh icle is R H steered eered ) in acco accor rd an ce w ith th e veh icle m an u fact ctu u rer’ s in stru cti ctio n s.

S   Put Pu t to o l[2 ] o n th th e st steeri eerin g w h heel eelan and d at att tach t th h e po in ter to t th h e das da sh b o ard ard o r to t th h e w in d screen (Fig. 11) . R aise th e en eng g in e sp eed to app ap p ro x. 1 0 0 0 r.p .m .. .. R ead th e id le p ressu essu re at th e p ress essu re g aug au g e. R o tate ate th e steeri eerin g w heel h eel to to th e left eft u n til a p ress essu re o f 1 b ar ab a b o ve id le p ress essu re is in d icated ed. . O n to o l [2 ], read th e d ial valu e. R o tate ate th e steeri eerin g w heel he el to th e rig h t u un n til a p ress essu re o f 1 b ar ab a b o ve id le p ress essu re is in d icated. C alculate ate th e to tal travel cover covered ed. . O n to o l [2 ], read ea d th e d ial valu e. M axim um value: 40 m m (steering w heel mm) For a versio n w ith b evel b o x: M axim um value: 45 m m (steering w heel mm)

50 0

50 0

If th th e m axim u m valu e is exc e xceed eeded ed, ,c ch h eck th e p lay o f th e steeri eerin g colu m n an d , if req u ired , rep air or o r rep lace th e steer ee rin g b o x. R em o ve th e ZF Servot Servotest est p o w er e r steeri eerin g tester. C h eck th e o il level and an d b leed th e steeri eerin g sysystem . See C hap ters V. and V I. 18

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

Fig. 11

 

In sp ecti ctio n /O ilC h an g e

6

Replac lacing ing the fi filt lte er

Attention: Pri Prio r t to o rem o vin g th e o il tan k cover co ver, th o ro u g h ly clean ea n th e tan k an d its im m ed iate ate en viro n m en e n t in o rd er to to p reven eve n t im p u rities fro m g ettin g in to th e h ydr yd rau lic o il. Pu ll th e filter in sert sert ou o u t of o f th th e o il tan k. O il d ro p s fro m th e filter in sert ert m u st n no ot g get et in to th e o il tan k. If th e o il is b ad ly so iled , clean ea n th e o il tan k. Fit a n ew filter in sert.

7

Carrying ing out out a test dr driv ive e

U p o n com p leti etio n o f th e in sp ectio n w o or rk, check th e steeri eerin g syst ystem fo r p ro p er fu n ctio n in g b y m ean s o f a test dr d rive.

V. Oil Oil Ch Change 1

Draining the oil

Note: A n o ilchan lch ang g e w illo n ly be b e n eed ed if u n its b elo n g in g to th e steeri eerin g syst ystem w ere ere repai ep aired o r repl ep laced aced. .

D o n o t ree-u u se th e o il o n ce it has b een d rain ed. ed . A lso , avoid any an y b lend en d in g o f oils.

1.1

Drain Draining ing the the ste teer ering ing syste ystem m

Jack u p th e steered eered axle   ¡   . U n screw th e p ress essu re and an d retu etu rn lin es a at t th e steer eeri in g b o x. Then have the the en engi gine run fo r a shor sho rt tim e ( (1 1 0 sec eco o nd s m ax axi im um ) to su ck th e o ilf lfr rom the p um p and fro m th e o il tan ank. k. A n y escapi escapin g o il m u st be collected. ed . Screw th e p ressu essu re an d retu etu rn lin es in ag ain .

¡   See ve veh h icle m an u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

19

 

O ilC hange han ge

1.2 Drain rainin ing g the the stee teering ring box box

Fig. 12

If exi existin g , o p en

S   th e screw p lu g s (5 5 ) o f th e cyl cylin d er cover o r th e h o u sin g S   th e set set screw and an d th e collar n u t, resp esp . (2 0 o r 1 2 8 ) S   the sc screw (20 o r 12 8) S   th e b leed er (5 7 )

(F (Fig ig . 12) 12) .

A qu ick drai draining can be achiev eved ed by op ening the on e am o ng the ab above ove com po nen ts w h hi ich is low es est t in th e in stalled p o sitio n .

R o tate ate th e steeri eerin g b o x b y h and an d fro m lo ck to lo ck u n til n o m o re o il is dr d rain in g . Th The e com p o n en ent ts th at h ad b een o p ened en ed m u st b e scr screw ed e d in agai ag ain , app ap p lyin g th e fo llo w in g tig h teni en in g torques: Screw p lu g (5 5 5) ):

4 0 N m (M 1 6 6x x1 .5 ) 50 N m (M 18x1. 18x1.5)

C ollar nut (21 and 129):

20+ 10 N m

Screw (2 0 an d 1 2 28 8 ):

12 2+ +3 Nm

B leed er (5 7 ):

30 N m

Note: Ev Even en if all com po nen ts m enti ention ed abo ve had been op ened , it m ay h app en that ther there e is a res esi idu al o il q u an tity left eft in th e steer ee rin g b o x. A com p let ete e d rain in g o f th e steeri eerin g g ear m ay b e n eces ecess sary ary d dep epen end d in g o n th e am o u n t o f im p u rities in th e o il. To th is eff effect, th e steeri eerin g g ear ha has st to o b e d ism o u n ted fro m th e vehi veh icle and an d o p ened en ed at a ZF Ser Se rvice C en tre.

2

Oil filling

Attention:

W h en th e steer ee rin g syst system is filled w ith h ydr yd rau lic o il, th ere ere is a risk o f im p u rities g ettin g in to th e steer ee rin g o ilcircui cu it. To avoi avo id m alfu n ctio n s cau sed b y fo reig n b o d ies in th e syst system , m axim u m clean ea n lin ess is o f par pa ram o u n t im p o rtan ce b o th at in itial fill an d w h en to p p in g u p w ith o il. 20

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

O ilC h ang an g e/B e/B leed ee d in g

A d m itted o il g rad es: p leas ea se refer efer t to o th e list o f lu b ricant can ts TETE -M L 0 9 Fill th e tan k w ith o il to th e rim . Star Start t th e en g in e an d h ave it ru n at id lin g sp eed ee d to fill th e steer ee rin g syst system w ith o il. D u rin g th is o p erat erati io n , th e o il level in th e tan k w ill q u ickly d ro p . Ther Th eref efo o re, to avoid any an y taki takin g in o f air, th e o il tank an k m u st co co n stant an tly b e to p p ed u p .

In ad d itio n , fo r veh veh icles w ith a g ro u n d -d riven em erg erg en cy steer ee rin g p u m p : Jack u p th e d rive axles  ¡   . Select a g ear and h ave th e eng en g in e ru n at id lin g sp eed eed. . To avoi avo id an y taki ak in g in o f air, con co n stan tly to p u p w ith o il.

VI.. Blee VI leeding ding S   For Fo r steer ee rin g g ear ea r versi versio n s w ith au to m a at tic b bl leed ee d in g : Steer Steeri in g g ear versio n s w ith aut au to m a at tic b leed in g d o n o t h ave any an y b leed screw s. Th ese ese steer eeri in g g ears ears au to m atically b leed ee d an y air rem ain in g w ith in th e steer ee rin g sys syst tem .

Note: A u to m ati atic b leed ee d valves o p erat erate e in th e id le p ress essu u re ran g e o n ly; th eref erefo o re an y u n n ecessar ecessary y p ressu essu re b u ild -u p sh o u ld b e avoi a void ed . W h en th e steeri eerin g syst ystem is filled to su ch an extent en t th at th e o illevel eveld d o es no t d ro p b elo w th e up u p p er m ar ark k o f th e o il d ip stick any an y m o re, h ave th e eng en g in e ru n fo r 2. 2.. ..3 m in u tes at lo w sp eed. eed . R o tate ate th e steeri eerin g w h eel several everal tim es fro m lo ck to lo ck and an d , w h ile d o in g so , w at a tch th e o il level. If req u ired , to p u p w ith o il.

S   A d d itio n ally, fo r veh veh icles w ith a g ro u n d -d riven em erg erg en cy steer ee rin g p u m p : Jack u p th e d rive axle   ¡   . W ith a g ear sel selected and an d th e eng en g in e ru n n in g , b leed th e em er e rg ency en cy s st teeri eerin g p u m p . 2 ...3 m in u tes later ater ro ro tate ate th e steer ee rin g w h eel ee l sever several al tim es fro m lo ck to lo ck.

Note: In th e en d p o sitio n s, d o n o t p u llh eavi ea vier at th e steeri eerin g w h eelt eel th an is n ecessar ecessary yt to o ro tate ate th e steer ee rin g g ear ea r.

If req u ired , to p u p w ith o il.

¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

21

 

B leed in g S   V ersi ersio n s w ith ad d itio n al p o w er cylin d er: er: The Th e lin e con n ectio n s o f th e p o w er cyl cylin d er m u st b e d irected u p w ard ard to allo w fo r th e air in th e cyl cylin d er an d in th e o il to escap escap e. If n ecess ecessar ary y, tu rn th e p o w er cylin d er accor accord d in g ly an a n d re-ass e-assem em b le it cor co rrectl ectly aft after b leed ee d in g . S   V ersi ersio n s w ith b leed ee d er (5 7 ):

Fig. 13 W ith th e en eng g in e ru n n in g , o p en th e b leeder eed er (5 7 ) u n til o il o n ly is com in g o u t (Fig. 13) . A fterw ar a rd s clo se th e b leed ee d er ag ain u n til it is o il-tig h t. O n versi versio n s w ith o u t au to m ati atic b leed ee d in g syst system (in stalled p o sitio n h o rizon zo n tal, steer ee rin g o u tp u t s sh h aft aft in th e b o tto m p o sitio n ) th e u p p erm erm o os st screw /set s scr crew (2 0 and an d 1 2 8 , resp esp ectively) can b e u sed fo r b ee  d iVer n gr.sio n s w ith scr Sleed Ve screw (2 0 an a n d 1 2 8 ): O pen th e u p p er erm m o st scr screw (2 0 and an d 1 2 8 , resp esp ectively) u n til o il o n ly is co com m in g o u t. Re-t Retigh ten the screw (20 or 128) 12 8) at 12 + 3 N m .

S   Ver Ve rsio n s w ith set screw (2 0 and an d 1 2 8 ): Slacken th e collar nu t (2 1 o r 12 9 ) o f th e u p p erm erm o st s set et scr screw (2 0 o r 12 8 ) u n til o il o n ly is com in g out. Tigh ten the collar nu t (21 and 12 9) at 20 + 10 N m . A fter th th e b leed ee d in g o p erat erati io n th e h ydr ydrau au lic steer eeri in g lim iter m u st be b e checke ch ecked d. S   A d d itio n ally, fo r vers versio n s w ith flan g e (3 3 5 )

Fig. 14

O pen th e screw p lu g (3 3 5 .4 ) u n til o il o n ly is com in g o u t (Fig. 14) . Th Then en clo se th e screw p lu g agai ag ain . Tigh tening tor orqu qu e: 8+ 1 N m (M 8 x1)

S   If bleedi eed in g w as do d o n e corr correctly, th e o il level eveli in th e o il tank an k m u st not no t rise b y m o re th an 1 o r 2 cm w hen th e eng en g in e is st sto p p ed. ed . Sto Sto p th e eng en g in e and an d lo w er th e jacked-u acked-u p steeri eerin g axle and an d d rive axle to th e g ro u n d .

¡   see ve veh h icle m an a n u factu ctu rer’ s in stru cti ctio n s 22

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

A d ju stin g th e H yd ydr rau lic Steerin g Lim iter

VII. VI I. Adjus Adjusting ting the the Hydra ydraulic ulic Stee teering ring Limite imiter r A n ad ju stm en t of of t th h e steer ee rin g lim iter is req u ired if o or r w h en

S   a n ew o r rep aired steer ee rin g b o x is fitted S   n ew scr screw s (2 0 an d 1 2 8 ) w ere ere fitted to th e au to m a at tically ad a d ju stin g steer ee rin g lim iter S   alterat erati io n s to to o r adj ad ju stm en e n ts of o f th e steer ee rin g lin kag ka g e w ere ere carr carried o u t.

1

Hydr Hydrau aulic lic ste teer ering ing limiter iter with mec mechanic hanical adju adjus stmen tmentt  (Fig. 15)

Fig. 15 Fit a p ress essu re g aug au g e (p ress essu re rang an g e u p to 2 5 0 b ar) ar) o r a ZF Servot Servotes est t po w er st steeri eerin g tester to to th e p res ess su re lin e b et etw w een th e p u m p and an d th e steeri eerin g g ear (see Fig. 16).

20

1 Pum p 2 O iltan ltank k 3 Pressu Pressur re lin e 4 Su ctio n lin e 5 R etu etu rn lin e 6 ZF-Se ZF-Ser rvot vo test

Fig. 16

12 8

A et to inng “ at set set scr screw caus se an in crease in o r a red redu u ctio n o f th e d ro p arm arm m o vem en t in (Fig. 16)(.1 2 8 ) w ill cau d irs eett cti B” A set ett tin g at set screw (2 0 ) h o w ever, w ill cause cause an in creas ease e in o r a redu ed u ctio n o f th e d ro p arm arm m o vem en t in d irect cti io n “A ”. In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

23

 

A d ju stin g th e H yd ydr rau lic Steerin g Lim iter

Test tem p erat eratu u re: 5 0   10 o C

S   R ig id axle: R elieve th e axle b y jacki ackin g it up up o r p pl lace it on o n sw ivel p lates ates¡   .

S   Si S in g le-w e-w heel he el su sp en sio n : Place th e steer ee red w h eels o n sw ivel p lates ates

S   W ith th e en eng g in e ru n n in g at idling speed peed, ro tate ate th e steer ee rin g g ear to to th e lo ck sto p . U p o n reach ea chi in g th e lo ck sto p , o vercom co m e th e retu etu rn fo rce o f th e steeri eerin g valve b y ro ro tati atin g th e steer ee rin g w hee h eel l fu rth er fo fo r a sh o rt tim e (5 sec. m axim u m ) u n til a fixed steer ee rin g sto p is reach reach ed .

R ead th e p ress essu re at th th e p ressu essu re g aug au g e o r t th h e ZF Servot Servotest est p o w er e r st steer eeri in g tester.

Sp ecified valu es: St S teer ee rin g syst ystem s u p to 1 6 d m   3 /m in : 4 0 ...5 0 b ar up to 20 dm   3 /m in : 5 0 ...6 0 b ar above 20 dm   3 /m in : 7 0 ...8 0 b ar

To corr correct, slacken th e corr corresp esp o n d in g collar n u t (2 1 o r 1 2 9 ) and an d screw th e set set screw (2 0 o r 1 2 8 ) Fig. 16  in o r ou t.

If a higher higher pressure is meas easured ured,,  th  th e cor corr resp esp o n d in g set scr screw m u st be  sc  screwed rewed in  f  fu u rth er. If a lower pr pres essur ure e is meas easur ured ed,,  th e cor corr resp esp o n d in g set s scr crew m u st be  screwed out  fu  fu rth er.

W h ile d o in g so , releas ea se th e steer eeri in g w h eel ee l so th at d u rin g th is w o rk th e id le p ress essu u re o n ly can b u ild up . N ex ext t, tigh ten the collar nut at 20 + 10 N m .

Attention: D u rin g th e sett ettin g o p erat erati io n as w ell as in th e b u ilt-in con co n d itio n th e set screw s (2 0 an d 1 2 8 ) m u st b e screw ed e d in at least 3 th read s d deep eep fo r o th erw erw ise, b ecau ecaus se o f in su fficient en t th read o verlap, ap , th ey w o u ld ru n th e risk o f bei be in g ejected ected w hen h en m axi a xim u m p ress essu u re is bu b u ild u p in th e steer eeri in g g ear.

¡   See ve veh h icle m an u factu ctu rer’ s in stru cti ctio n s

24

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

A d ju stin g th e H yd ydr rau lic Steerin g Lim iter

Pro Pro ceed as d escr escrib ed abo ab o ve to carry o u t th e ad ju stm e en n t fo r th e secon d lo ck sto p .

Note: A t vari varian ce w ith th e sett ettin g d escr escrib ed ab o ve, th e vehi veh icle m an u fact actu u rer m ay sp ecify a d ifferen eren t w ay ay o f ad ju stm en t, e.g e.g . b y in sert ertin g a sp acer to en su re th at, at, w h en th e steer ee rin g lim itati atio n respo n d s, th ere ere is a d istan ce d im en sio n “C ”(Fig. 17) .

Fig. 17 

Lock stop A xle sto p

2

Autom Automat atic icall ally y adjus adjusting ting hydr hydrau aulic lic ste teer ering ing limite limiter r  (F  (Fig ig . 18 18))

Fig. 18

Attention: Steerin g g ear Steeri ea rs fitted w ith an au to m atically ad ju stin g h ydr yd rau lic steer ee rin g lim iter m u st n no o t b e ro tated m an a n u ally to to th e end en d p o sitio n s w hen h en th e steeri eerin g lin kag e is rem o ved o r w hen h en th e steeri eerin g g ear h as b een rem o ved fro m th e vehicle, fo r th e slid in g b u sh es o of f th e screw s (2 0 and an d 1 2 8 , respect especti ively)w y) w o u ld th ereb ereby y b e sh ifted to th e cut cut-o ff p o sitio n th at is at m axim u m p o ssib le and an d an aut au to m ati atic a ad d ju stm ent en t o n th e vehi veh icle w o u ld o n ly b e p o ssib le w ith   new  scr  screw s (20 and 12 8) (Fig. 19) . The screw s ( (2 2 0 and 12 8) and the set screw s (20 and 12 8) can   not   be exc exch h ang an g ed agai ag ain st each o th er.

Fig. 19  In itial p o sitio n Slid in g b u sh es n o t ad ju sted yet

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

25

 

A d ju stin g th e H yd ydr rau lic Steerin g Lim iter

2. 2.1 1

Func unctioning tioning of the autom automatic atically adjus adjusting hydra hydraulic ulic steer teering ing limiter limiter

In th e end en d p o sitio n s, th e valve p isto n tapp ap p ets ets r ru u n u p agai ag ain st th e slid in g b u sh es o f th e screw s (2 (2 0 o r 1 2 8 ) an d o p en th e steer ee rin g lim iter valve elem en t (U o r T). Th e o p en in g o f th e steer ee rin g lim iter valve is d eter eterm m in ed b y th e p o sitio n o f th e slid in g b u sh es o n th e screw s (2 0 and an d 1 2 8 ).

2.2 Sett ttin ing g Note: Th is settin g   (Fig. 20)   can o n ly b e m ad e aft after t th h e steeri eerin g g ear h as b een fitted to th e vehicle. T To o en ab le th e sett ettin g , th e steeri eerin g lin kag e an d th e axle sto p s m u st be fitted an d set. et. Sh iftin g

Fig. 20   Set Se ttin g o p erati eratio n Po sitio n in g o f th th e slid in g b u shes she s A xle sto p

D  F Fo o r veh veh icles w ith a rig id axl axle: R elieve th e steer ee rin g axle b y liftin g it slig h th ly (h o w eve ever r th e w h eel ee ls m u st still h ave g ro u n d con co n tact) act) o r p lace it on o n sw ivel p lates ates  ¡   .

D   For Fo r vehi veh icles w ith sin g le-w e-w h eel ee l su spe spen n sio n : Place th e w h eels o n sw ivel p lates. ates.

D   R o tate ate th e steer ee rin g w heel h eel w ith an d w ith o u t hydr hyd rau lic as a ssistan ce to th e m axim u m lo ck sto p . Th is w ill caus cau se th e p isto n to p u sh th e slid in g b u sh o n th e screw (2 0 and an d 1 2 8 ) u p to th e requ eq u ired cutcut-o ff p o sitio n   (Fig. 21) .

Note: D u rin g th is sett settin g o p erat erati io n th e steer ee rin g lim iter valve is co con n stan tly o p en w h ich m ean ea n s th th at, at, w ith as w el e ll as w ith o u t hyd h ydr rau lic ass assi istan ce, th e steer ee rin g w h eel can o n ly b e ro tated ated fu rth er at an in creas ea sed m an u al steer ee rin g eff effo rt. R ep eat ea t t th h is sett settin g o p erat erati io n in th e o th er d irecti ectio n o f ro tati atio n .

Fig. 21 Le Lef ft-h an d steerin g lim itatio n val valve o p en, en , o il p ressu essu re h ig h ly red redu u ced

¡ 26

 

see ve veh h icle m an u factu ctu rer’ s in stru cti ctio n s

C ut-off off po int D rop arm arm travel

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

A xle st sto op

 

R epai ep air o f Extern ern alLeakag alLeaka g es

2.3 Corre orrec cting ting the the dr drop op arm arm tr tra avel vel To   inc incre rea ase the the drop drop ar arm m tr trav ave el  (to o m u ch clear earan ance ce at th e lo ck sto p com p o n ent en ts): adj ad ju st as d deescrib ed ab o ve.

 reduc uce the the drop drop arm tr trav ave el (n o m o re clear To  red earan ance ce at th e lo ck sto p com p o n ent en ts, o r th e o ilp ressu essu re d o es n o t dr d ro p to th e sp ecified valu e (C h apt ap ter V II., Sect Secti io n 1 ) at th th e axle sto p ): Fit new screw s (2 0 o r 12 8 ).

Attention: Pul Pu llin g b ack th e slid in g b u sh o n th e screw s (2 0 and an d 1 2 8 ) is n o t adm ad m issib le Tigh tening tor orq q ue for sc screw s (20 an and d 12 8) 8): : 12 + 3 N m

VIII.. Repair VIII epair of Exte Externa rnall Leaka eakage ges s

dep end ing on the case case

Fig. 22

dep end ing o n the cas ase e

1

Valv lve e in ins sert (22) - pressure re relie lieff valv valve e Screw th e valve in sert ert (2 2 ) o u t o f th e h ho o u sin g  (Fig. 22) . R em o ve an y O -rin g rests. If th e p ressu essu re is n o t in con co n fo rm ity w ith th e sp ecified valu e o r if th th ere ere is an y leakag ea kag e, rep lace th e com co m p lete ete va val lve in sert sert (2 2 ). Screw th e valve in sert ert (2 2 ) in alo n g w ith a n ew g reas ea sed O -rin g (2 3 ). Tigh tening tor orqu qu e: 30 + 10 N m

2

Valve Valve ins insert (32) - re repl ple enis nishment ent va valve Screw th e screw (3 0 ) and an d th e valve in sert ert (3 2 ) o u t. Put Pu t th e valve in sert ert (3 2 ) in to th e h o u sin g b o re. R em o ve any an y O -rin g rests. Screw th e screw (3 0 ) in alo n g w ith a n ew g reased O -rin g (3 1 ). Tigh tening tor orqu qu e: 30 + 10 N m

3

Screws (20 and 128) Sc Scr rew in new screw s (20 and 12 8) Tigh tening tor orqu qu e: 20 + 10 N m A d ju st th e steerin g lim iter.

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

27

 

R ep lacin g an d Settin g th e Sw itch (2 2 2 )

4

Coll lla ar nuts (21 and 129) Screw in n ew collar n u ts (2 1 and an d 1 2 9 ). Tigh tening tor orqu qu e: 20 + 10 N m A d ju st th e steerin g lim iter.

5

Screw plug lug (55) Screw th e screw p lu g (5 5 ) o u t, fit it w ith a n ew sealin g rin g (5 4 ) and an d screw it in agai ag ain . Tight ghteni ening tor orque: que: 40 N m (M 16x1.5) 50 N m (M 1 8 8x x1 .5 )

6

Blee leeder (57) Screw in a n ew b leeder eed er (5 7 ). Tig ht hteni ening to rqu e: 30 N m

Attention: Excep Exc ep t th e w o rk d etai etailed ab o ve, n o fu rth er rep air w o or rk m ay b e carried o u t. R epai ep air w o or rk exceed exceed in g th e w o rk d es escr crib ed abo ab o ve m u st be carried o u t by a ZF Servi Service C ent en tre.

IX. Replac placing and and Setting tting the the Switc witch h (222) R epl ep lacin g th e sw itch (2 2 2 ) (tig h teni en in g to rq u e: 5 0 N m ). Fro m m id p o sitio n , tu rn th e steeri eerin g g ear t to o th e left eft an and d to th e rig h t. The Th e con tact of sw sw itch (2 2 2 ) o o m ust op en after a d rop arm trav avelo elo f 5 (   10% 10 % ), ea. (corr corresp esp o n d in g to 1 1 0    1 0 % at th e s st teer eeri in g w heel h eel = 0 .3 steeri eerin g w h eel tu rn s) (Fig. 23) . M ake su re th e steer ang an g les t to o th e left eft and an d to th e rig h t are are u n ifo rm an d , if req u ired , cor co rrect th e sym m etr etry o of f th e sw itchin g ran g e b y ro ro tati atin g th e cover co ver (2 2 1 ). Tig h ten in g to rq u e: C ap screw s (22 3 ): 5. 5.5 5 Nm

Fig. 23

Testin g to o l: m u lti-p u rp o se m eas Test ea su rin g in stru m en t (m u ltim eter)

Note: The Th e sw itchin g rang an g e is set b y varyin g th e screw -in d ep th o f th e sw itch (2 2 2 ).To d o so , w ashers ashers (2 2 2 .1 ) o f d ifferen eren t th ickn esses are are ava avai ilab le. D o n o t use m o re th an 3 w ashers ashers ( (2 2 2 2 .1 ) fo r t th h e sett ettin g o p erat erati io n . (a w asher th th ickness of o f app ro x. 0. 0.25 25 m m corr corres espo po nd s to a dr drop op ar arm m trav avel el of 1o = 22 o at th th e steer ee rin g w h eel ee l). The Th e cover (2 2 1 ) m u st be filled w ith 5 0 cm   3 o f oi o il (see char cha rt o of f lu b ricant can ts TETE -M L 0 9 ).

28

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

R epl ep lacin g and an d Set Se ttin g th e Pot Po ten tio m et eter er (2 3 2 )

X. Replac placing and and Setting tting the the Potentiom otentiome eter ter (232) 1

Removin oving g the the pote potent ntiom iometer ter (232)

Fig. 24 R o tate ate th e steeri eerin g b o x to m id p o sitio n . C lean th e p o ten ent tio m eter eter (2 3 2 ) envi en viro n m ent en t (Fig. 24) . M ark ark th e p o sitio n o f th e p o ten tio m eter eter (2 3 2 ). Screw o u t th e cap screw s (2 3 5 ). R em o ve th th e p o ten ent tio m eter eter (2 3 2 ) alo n g w ith th e screen sh eet (2 3 4 ), th e sp acer tu b e (2 3 3 ) and an d th e O -r -rin g (2 3 2 ).

2

Fittin itting g the the pote potent ntiom iometer ter (232)

C h eck w h eth eth er th th e steeri eerin g b o x is in m id p o sitio n . Fit t th h e O -r -rin g (2 3 2 .1 ) to th e p o ten tio m eter eter ( (2 2 3 2 ). Place th e d eep g ro o ve o f th e p o ten tio m e et ter (2 3 2 ) d rive o n th e d river (2 3 0 ).

Note: A s th e slid er o f th th e p o ten tio m eter eter (2 3 2 ) is sp rin g -lo ad ed , it w ill retu etu rn to its in itial p o sitio n w h en d isass sassem b led . Therefor Theref ore, e, check check w het h ether her the the po tenti entiom et eter er (23 2) ca can n b e tur urned ned thr hrou ou g h 50 o m in im u m to eith er sid e w h en th e steer ee rin g b o x is in m id p o sitio n . Fasten th e p o ten Fast ent tio m eter eter (2 3 2 ) alo n g w ith th e sp acer tu b e (2 3 3 ), th e screen sh eet (2 3 4 ) and an d th e cap scr screw s (2 3 5 ). Tig h ten eni in g to rq u e: 2 .8 N m C heck: heck: The Th e in stalled p o sitio n o f t th h e p o tent en tio m eter eter (2 3 2 ) m u st co cor rrespo n d to th e p o sitio n m arked arked d u rin g d isassem sassem b ly.

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

29

 

R epl ep lacin g and an d Set Se ttin g th e Pot Po ten tio m et eter er (2 3 2 )

3

Sett ttin ing g the the pote poten ntio tiom meter eter (232)

Attention: A m axim u m value of 6 V m u st no t be ex exc ceeded as o ther herw w ise the po tenti entiom eter (23 2) w ou ld be destroyed. The Th e tu m b ler sw itch o f th th e Ser Servot votr ro n ic Tester (t (to o l [8 ]) m u st no n o t be b e sw itched to sp eed o p o sitio n as o th erw erw ise th e p o tent en tio m eter eter w o u ld b e d est estro yed yed. .

R o tate ate th e steer ee rin g g ear ea r to m id p o sitio n (b y d di ivid in g th e to taln al n u m b er o f steer ee rin g w h eelt ee ltu u rn s in tw o ).

S   Sett ttin ing g a volta voltage ge of 5V C o n n ect to o ls [7 ] and an d [8 ] (o r u se a su itabl ab le trans an sfo in stead o f to o l [8 ]) and an d th e M u ltim et e ter as s sh how n in   Fig. 25 . 5V

Sw itch th e tu m b ler sw itch o n th e Servot Servotr ro n ic Test Tes ter (t (to o l [8 ]) to th e con co n ver vert ter p o sitio n .

Fig. 25

C o n tin u e adj ad ju stin g th e con verter regu eg u lato ato r u n til th e M u ltim eter eter sho sh o w s 5 V.

Tool[ Too l[8 ] red   b bl lu e

green

C abl ab le colou r b lac ack k

Tool[ Too l[7 ]

C abl ab le colo ur w h ite red

green b lu e

S   Setting etting the the potentiom potentiometer eter (232 (232)) to stee steering ring gea gear r mid mid position C o n n ect to o ls [7 ] an and d [8 ] and an d th e M u ltim eter eter as sh sh o w n in   Fig. 26 .

Fig. 26 Tool[ Too l[8 ] C abl ab le co col lou r

green

red b lu e

Tool[ Too l[7 ]

C ab abl le colo u r red

green b lu e

R o tat ate e th e p o ten ent tio m eter eter (2 3 2 ) to g eth eth er w ith th e cover (2 2 1 ) u n til th e M u ltim eter eter sh o w s h hal alf o f th e voltag age e ap app p lied ed, , n am ely 2 .5 V + 0 .0 3 V. In th is po p o sitio n , tig h ten th e cap screw s (2 (2 2 3 ) (tig h ten in g to rq u e: 4 + 1 .5 N m ). ). 30

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

R em o vin g th e Stee Steer rin g G ear ear

XI. Removi Removing ng the Steering Steering Gear 1

Tho Th o ro u g h ly cl clean th e steer eeri in g g ear and an d its im m ed edi iate ate en viro n m en ent t, in p art articular th e p ip e con n ecti ectio n s.

2

D rain the the o il as d es escr cribed in C hap ter V..

3

U nscr nscrew th e pres ess sur ure e and ret retur urn n lin es es. .

4

O b tu rate ate all o il p ip es (d ang an g er o f so ilin g ).

5

C heck w hether hether the m ar arks ks on the sec ect tor shaf shaft t and the dr drop op arm are in align m ent. ent.

Note: If th e m arks arks are are o ffset fro m each ea ch o th er, p rio r to fittin g th e d ro p arm arm in q u ire w ith th e veh ve h icle m an u factu rer w h eth er di d ifferin g asse ssem b ly in stru cti ctio n s exist. 6

Pull of off f the drop drop arm arm us usi ing too too l [6] 6]. .

Attention: H eating up the dr drop op ar arm m o r d riving in a w edge ed ge betw betw een th e h ou sing and th e d ro p ar arm m o r rem o ving th e d ro p ar arm m b y m eans o f ham m er b low s is no t perm perm itted as such such ac act tio n m ay cause cause chang es to the m ater ateri ial and an d /o r in n er dam d am ages ag es t to o th e steer eeri in g b o x.

7

In ad d itio n , fo r vehi veh icles w ith ad ju stab le steeri eerin g col co lu m n n: :

S   A d ju stt st th e d river’ ver’ s w o rkp lace to th e h ig h est p o sitio n in o rd er to relieve th e b all-track relay sh shaft aft as m u ch as p o ssib le. S   B y m ean ea n s of o f a suitab le to o l, fo r in stan ce a lash ashi in g b elt, relieve th e b all-track relay sh shaf aft t in such a w ay th at no n o th ru st fo rce can act to w ard ard s th th e steeri eerin g b o x. W h en a lash ash in g strap is us u sed, ed , p ass ass t th h e strap th ro u g h th e yok yoke e sp aces (see th e arr arro w s in   Fig. ), if p o ssib le. Tens en sio n th e strap to an extent en t avoi avo id in g a d am ag a g e to th e sealin g com p o n ent en ts  27  o r th e p ro tectio n cap o f th e steer eeri in g b o x caus cau sed b y a d islo catio n o f th e u n iversal jo in ts w h en u n screw in g th e clam p screw s.

8

Slacken th th e u n iversaljo in t o r th e elast astic cou p lin g bet b etw w een th e steeri eerin g b o x an and d th e steeri eerin g colu m n o r th e separ ep arat atel ely m o u n ted b evel evelb b o x.

9

Sc Scr rew o ut the m ou nt nti ing screw s and rem ove th e s st teeri eerin g gear.

Fig. 27  Note: If a fittin g b o lt w as u sed sed, , w rite d o w n its p o sitio n .

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ect ecti io n

31

g ,

g,

p

 

In stallin g th e Steerin g G ea ear ag ain

XII.. Insta XII Installing lling the Stee teering Gea Gear again gain

Attention: To g u aran arant tee a safe afe fu n ctio n in g o f t th h e steer eeri in g syst ystem , m axi a xim u m clean lin ess is an abs ab so lu te m u st w h en in stallin g all u n its th at ar a re p art art o of f th th e syst ystem .

Note: To avoi avo id m alfu n ctio n s cau cau sed b y fo reig n b o d ies o r im p u rities in th e o il circui cu it o of f th e steer ee rin g g ear ea r, th e p lu g s in th e p o rts of o f th e steer ee rin g g ear, th e o il p u m p , th e steer ee rin g cylin d er, th e valves et etc. c.s sh o u ld o n ly b e rem o ved at th e m o m ent en t th e lin es ar are e con n ected. ed . R em o ve p ro tectin g sleeves in th e in stalled con d itio n o f th e steeri eerin g b o x,o n ly, if th is is p o ssib le. C o n n ectin g lin es and an d screw ed con n ectio n s m u st be tho rou gh ly cleaned and d ebu rred.

1

R o tat ate e th th e steeri eerin g w heel to th e straig h t ahead ah ead d rivin g p o sitio n .

2

C lean th e m ou o u n tin g b racket and an d steer eeri in g g ear lo catin g su rfaces. aces.

3

For Fo r veh icles w ith an ad ju stab le d river’ ver’ s w o rkp lace ace, , in ad d itio n :

Fig. 28

U sin g a suitab le to o l, fo r in stan ce a lash ashi in g strap , d raw th e b all-track relay sh shaf aft t to g eth eth er u n til th e steer ee rin g b o x can b e b u ilt in ag ain w ith o u t com co m p ressi essin g th e b all-track relay sh aft aft (Fig. 28) . 4

R o tat ate e th th e steeri eerin g g ear to m id p o sitio n b y divid in g th e to tal n u m ber b er o f steeri eerin g w heel tu rn s  Fig ig . 29) o n th e in p u t sh aft in tw o . Th en con co n tin u e to ro tate ate u n til th e m arks arks (see  F aft, th e p ro tectio n cap an and d th e h o u sin g coin cid e.

32

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In stallin g th e Steerin g G ea ear ag ain

Fig. 29 m ark h o u sin g m ark

p ro tectin g cap stee eer rin g in p u t sh aft

m ark

m ark

sect ecto o r sh aft

stee eer rin g d ro p arm

5

Place th th e steeri eerin g b o x in to th e m o ou u n tin g b racket and an d fast asten it w ith screw s. s.

Note: M ake ak e sure sure th e p o sitio n o f t th h e fittin g b o lt is cor co rrect ect. . Tig h ten in g to rq u e: see techn ech n ical cove cover r sh sh eet o f th e sp are are p art arts list. If no n o d ata ata is gi g iven in th e cover cove r sheet she et, , th e fo llo w in g valu es sh all ap p ly.

D ep epen end d in g o n th e vehicle type, a p revio u s fitm en t o f th e d ro p arm arm m ay b e n ecess ecessary ary b because ecause o f spa sp ace restrict cti io n s. Tig h ten in g to rq u es: Th read M 1 8 x1 .5

Screw g rad e 1 0 .9

Tig h ten in g to rq u e 4 1 0 1 0 % N m

M 2 0 x1 .5

1 0 .9

5 2 0 1 0 % N m

Attention: C o n fo rm to th e veh icle m an u fact actu u rer’ s in stru cti ctio n s.

6

Fit th e u n iversaljo in t o r th e elast astic c co o u p lin g b etw etw een th e steeri eerin g colu m n and an d th e steeri eerin g b o x.

Note: Th The e clam p in g slo t in th e u n iversaljo in t m u st p o in t to w ard ard th e m ark ark o n th e cover co ver cap o r o n th e in p u t sh aft aft.

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

33

 

In stallin g th e Steerin g G ea ear ag ain

7

In ad d itio n , fo r vehi veh icles w ith an ad ju stab le d river ver’ ’ s w or orkp lace ace: : Put Pu t o on n th e u n iversal jo in t w ith o u t d dam am agi ag in g th e steer eeri in g b o x seal. Tig ht hten en th e clam p screw (M 10 x1,25 ) at 48 + 5 N m .

Cautiously   relieve th e to o l, e.g e.g . th e lash ashi in g strap , see  Fig. 28 , and an d rem o ve it. 8

M o ve th th e steered eered w heel he els of th e vehicle to th e straig h t ahead ah ead d rivin g p o sitio n . Th is p o sitio n is rea reach ched ed w h en th e steer ee red w h eel ee ls a ar re in lin e w ith o r p aral arallelt el to , resp espect ecti ively, th e secon eco n d p air of o f w h eels (p lace a g radu ad u ated ated ru ler ag ain st t th h e fro n t an d rear w h eels).

9

Put the d rop arm on the ser serr ration and m ake sur ure e that the m arks on the d rop arm and on the secto sect o r shaft sh aft coi co in cid e  (see Fig. 29) . Screw o n th e lo ckin g n u t (5 0 ) and an d tig h ten it, app ap p lyin g th e tig h teni en in g to rq u es as d etai etailed b elo w .

S   For Fo r versi versio n s w ith tap ered ered ser serr ratio n :

Note: For th e tig h ten in g to rq u es p leas ea se refer efer t to o th e tech echn n ical cover co ver she sheet et o f th th e sp are are p art arts list. If n o d ata ata is g iven th ere, ere, th e fo llo w in g valu es sh all ap p ly.

Threa ead d

Se Ser rration

Tighteni ghtening torque orque

M 30x 30x1. 1.5

1 3/8“x36

250 N m +10%

M 30x 30x1. 1.5

1 1/2“x36

300 N m +10%

M 30x 30x1. 1.5

1 5/8“x36

330 N m +10%

M 3 5 x1 .5

400 N m + 10%

M 4 2 x1 .5

500 N m + 10%

M 4 5 x1 .5

550 N m + 10%

Exc Exception

M A N : 850 N m + 10%

If th th e veh icle m an u factu actu rer spe speci cifies d ifferen eren t valu es, th ese valu es m u st be be ap p lied .

S   For Fo r versi versio n s w ith cylin d rical serr serratio n o r clam p screw s: U se th e tig h ten in g to rq u es sp ecified b y th e vehi veh icle m an u fact actu u rer.

34

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

In stallin g th e Steerin g G ea ear ag ain

10

Peen Peen the locki ocking nu t (50 ) as sho w n in   Fig. 30 . ¡

Fig. 30

at lea eas st 1 .5

11

Put Pu t th e d rag lin k o r th e ti tie r ro o d in to p lace a an n d tig h ten it. ¡ R o tate ate th e steer ee rin g g ear ea r to th e left eft u un n til reach ea chi in g th e sto p . Take ak e o ff th e d rag lin k o r th e tie ro d .

12

A d d itio n ally, fo r ver versi sio n s w ith au to m a at tically ad a d ju stin g steer ee rin g lim iter Sc Scr rew ou t scr screw s (20 an and d 12 8) 8). .

13

C h eck at th e steeri eerin g w h heel eel w het h eth h er any fu rth er m o ovem vem ent en t to th e left eft is po p o ssib le. If th e steer ee rin g g ear cann can n o t b e ro ro tated ated an y f fu u rth er to th e left eft, th e lo ck sto p o r th e axl a xle sto p m u st b e re-set. e-set.

Attention: It m u st be b e g u aran aran teed ee d th at steeri eerin g an g le lim itati atio n takes ake s p lace at th th e lo ck sto p s o r th e axle sto p s and is not n ot don d on e by the steeri eering bo x.

14

Put Pu t th e d rag lin k o r th e ti tie r ro o d in to p lace a an n d tig h ten it. ¡ R epeat ep eat th e check che ck fo fo r th e rig h t-h and an d sid e and an d , if n ecess ecessary ary, re-s e-set th e lo ck sto p o r th e axle sto p .

15

In ad d itio n , fo r versi versio n s w ith au to m a at tically ad a d ju stin g steer ee rin g lim iter

Sc Scr rew in screw s (20 and 12 8) 8). . Tigh tenin g tor orqu qu e: 1 2+ 3 N m

16

¡

Put Pu t th e d rag lin k o r th e ti tie r ro o d in to p lace a an n d tig h ten it. ¡  

see veh ve h icle m an u factu ctu rer’ s in stru cti ctio n s

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

35

 

In stallin g th e Steerin g G ea ear ag ain

17

C on nect the p res ess sur ure e and ret etur urn n lines b et etw w een th e p um p, the steeri eerin g gear and th e steering cy cyl lin d er.

18

Fill th e st steeri eerin g syst ystem w ith o il Refer Ref er to C hap ter V.

19

B leed th e st steeri eerin g sys system

R ef efer er to to C h ap apt ter V I.

20

Set Se t th e h ydr yd rau lic st steer ee rin g lim iter R efer efer to to C h apt ap ter V II.

21

C heck heck the oil lev evel el

B efo efo re extr extracti actin g th e o il d ip stick, th o ro u g h ly clean ea n th e o il tan k an d its im m ed iate ate en viro n m en t t to o p reve even n t di dirt fro m g ettin g in to th e h ydr yd rau lic flu id .

Attention: If th th e o il level evel is to o lo w , it can en tail m alfu n ctio n s cau sin g a failu re o f t th h e h ydr yd rau lic steer eerin g assi assistance.

For vehic vehicles fitted fitted with a ZF Ser ervoc vocom RAS (rear rear axle ste teer ering ing)), in addit addition ion:: C h eck th e o il level in th e straig h t ahea ah ead d d rivin g p o sitio n . If th th e o il level is ab abo o ve th e u p p er m ark, ark, th ere ere m a ay y b e a leakag e in th e m ast aster cyl cylin d er of of t th h e ZF Servocom RA S.

36

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

Sp ecialTo o ls

XIII. XII I. Spec pecial Tools Note: Th e to o ls desc d escr rib ed b elo w are are u n ivers versal to o ls. For Fo r sp ecialap al ap p licat cati io n s, sp ecialt al to o ls recom eco m m en d ed b y th e vehi veh icle m an u factu actu rer m ay, ay, th eref erefo o re, b e n ecessar ecessary y.

Ordering Order ing Ref. No.

Tool [1] [1] ZF Servo test 5 7 0 p o w er steerin g tester w ith flo w con co n tro l valve 2 d m   3 /m in

7418 798 574

Tool [2] [2] D ial w ith p o in ter

7418 798 452

Tool [3] Yo ke [3]

7418 798 556

Tool [4] [4] 1 p air of o f expan expand d in g d evices

Tool [5] [5] To rq u e m eter

 

7418 798 653

7418 798 703

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

37

 

Sp ecialTo o ls

Ordering Order ing Ref. No. Tool [6] [6] Extr Ext racto acto r fo fo r dr d ro p arm arm Ext xtr rac act tin g d evice

7418 798 202

H ydr yd r. extr extracti actin g d evice co con n sistin g o f: H an d p u m p

7016 798 201

C ylin d er

0646 121 048

B ell fo r secto r sh aft d ia.s u p to 4 5 m m

7418 798 214

fo r s sect ecto r sh sh aft aft d di ia.s fr fro m 5 5 m m , d ro p arm w id th s u p to ap p ro x. 1 0 2 m m

7418 798 213

fo r s sect ecto r sh sh aft aft d di ia.s fr fro m 5 5 m m , d ro p arm w id th s u p to ap p ro x. 1 2 0 m m

7418 798 216

Tool [7] [7] A d ap ter cab le

7418 798 567

Tool [8] [8] Servo tro n ic tester

7418 798 545

38

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

Tro u b le Sh o o tin g

XIV. IV. Troub rouble le Shootin ooting g Fault

Cause

Remedial action

stiff operat operation to eithersi herside

oillevel evelt too low

repair leaka eakage ge to p u p w ith o il¢

steerin g syst system is takin g in air

rep air leaka ea kag ge

(suct sucti io n area)

to p u p w ith o il¢ b leed steerin g syst system   £

stiff o p erati eratio n in o n e d irectio n

stiff o p erati eratio n o f u n iversal versal

check

jo in ts/steerin g col co lu m n

rep lace  ¡

o ilfilter s so o iled

rep lace  ¥

steerin g d ef efective

rep ai air © rep lace  ©

p u m p d efective

rep air © rep lace  ©

in cor co rrect sett settin g o f

ad ju st ¤

ste steerin g lim iter steerin g d ef efective

rep ai air © rep lace

stiff o p eratio n d u rin g

steerin g syst system is takin g in air

fast steer ee rin g m o tio n

(suct sucti io n area)

rep air leaka ea kag ge to p u p w ith o il¢ ee steern g s sy ys em

n o ise

p u m p d efect efective or w ro n g vers versio n air in th e o il

repl ep lace pu m p © b leed steerin g syst system   £

o illeveltoo eve ltoo lo w

to p u p w ith o il¢

p u m p d efective

rep air © rep lace  ©

¡

 

see ve veh h icle m an u factu ctu rer’ s in stru cti ctio n s

©   app ap p ro ach ZF Servi Service C ent en tre ¢   see C hap ter V.

   

 

£   see C h apter apter V I. ¤   see C h apt ap ter V II. ¥   see C h apt ap ter IV.

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

39

 

Tro u b le Sh o o tin g

Fault

Cause

Remedial action

self centr centring ham p ered

ax axl le/ax axl le gu ide com p on ents ents

rep air ¡

stiff o p eratio n steer ee rin g g ear ea r/steer ee rin g col co lu m n

elim in ate

fitted in tw isted p o sitio n

tw istin g   ¡

stiff o p erat erati io n o of f steer ee rin g co col lu m n

rem ed ed y stiff o p eratio n   ¡

steerin g d ef efective

rep ai air © rep ace  ©

n o p recise straig h t ah ead ea d

o illevelto o lo w

rep a ai ir leakag e

d rivin g p o ssib le

to p u p w ith o il¢ b leed steerin g syst system   £ axle/axl e/axle g u id e com co m p o n en ts/

check  ¡

steer ee rin g col co lu m n n o t p lay fr free

rep lace  ¡

steering notplay free

chec heck  ¥ rep lace  ©

For Fo r ver vers sio n s w ith p o ten tio n m eter eter ( (2 2 3 2 ) in ad d itio n :

Pin n in g at p o ten tio m eter an d p lu g (veh icle circui rcu it)

3 2

1

2 3

1 4

23 2

n o fu n ctio n o f p o tent en tio m eter eter no service voltage (2 3 2 )

atp lug (vehicle circuit) m easu easu re b etw etw een p in s 1 -3 spe specified val valu e: servi service vol vo ltag e¡

conta ontactpr tprobl oblem s

rem ove ove dirtand/orc orcor orr rosi osion

40

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

Tro u b le Sh o o tin g

Fault

Cause

Remedial action

int nter ernaldi naldistur urbance bance

tes est t po tenti entiom eter(s er(see below )

p o tent en tio m eter n o t d riven (2 3 2 )

repl ep lace steeri eerin g b bo ox ©

w ro n g fu n ctio n in g o f p o tenen - w ro n g settin g tio m eter eter (2 3 2 )

set p po o ten tio m eter ¦

w ro n g w irin g

ch eck w irin g   ¡

cap sc screw s (22 3 and 2 35 )loo se

check and /or tigh ten   ¦

w ro n g in stallati atio n o f p o ten tio m e- check ¦ ter (2 3 2 )

¡

 

see ve veh h icle m an an factu ctu rer‘ s in stru cti ctio n s

©   app ap p ro ach ZF Servi Service C ent en tre ¢   see C hap ter V. £   see C hap ter V I. ¤   see C hap ter V II ¥   see C h ap apt ter IV. ¦

 

see C hapter hapter X .

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

 

K ey t to o N u m b er ers s in Fig u res an and d Explo d ed D raw in g

XV.. Key XV Key to Numbe umbers rs in Figure igures s and Explod xplode ed Drawing rawing

20

Set screw /screw

2 0 .1 20 .9

O -rin g Sc Scr rew

21

C ollar nut

22

Valve ins nser ert

23

O -ring

30

Screw

31

O -ring

32

Valve ins nser ert

50

Lock ocking nut

54

Sealing ring

55

Screw plug

57

B leed e er r

128

Set screw /screw

1 2 8 .1 O -rin g 1 2 8 .9 Screw 129

C ollar nut

41

42

Inst nstructions on D esi esign,Funct gn,Functioning,M aintenanc ntenance e and Inspec nspect tion

 

O rig in alf al fo r d u p licat cati in g (Pag Pa g e 1 )

In sp ecti ctio n rep o rt fo r ZF-S F-Servo ervoco com m steer ee rin g g ge ear ars s C u sto m er: .................................... Steerin g g ear versio n : ..................... V eh icle m an u factu rer: .......................... Pu m p m an u factu rer: ...................... V eh icle typ e (o r m o d el): .... ...... .... .... .... ... ..... ...... .... .... ... . Pu m p versio n : ..... ...... .... .... .... .... .... .... ... ..... ...... .... .. M ileag e: ...................................... Em erg en cy steerin g p u m p : .................  

Sin g le-w e-w h eel su sp en sio n

 j

 

 

Leaf Lea f sprin g

j

Inspection work: Inspec work: 1 Ins Inspec pection tion inte interv rva als (see Chapt hapte er IV IV.) .) 2

Vis Visual ual ins inspec pection: tion: Fit of mounting screws screws:: sp ecified tig h ten in g to rq u e check ch ecked ed

 

j   yes   j   r re e-tig h ten ed

Straight traight ahead ahead driving position: position: Str Straig h t ahead ah ead p o sitio n o f w heel h eels checked ch ecked, , w ith th e m arks arks o n in p u t sh sh aft aft and an d valve h o u sin g coin cid in g (n u m b er o of f st steer eeri in g w h eel tu rn s d ivid ed in tw o )   j   yes   j   co rrecte cted Play betwee between n piston piston and and sector shaft haft in mid position: In creas ea se in frictio n al to rq u e (as com p ared ared w ith o u tsid e th e h ig h sp o t) checke ch ecked d  j   yes   j   re-set

Steering motion: Steering Steer Steeri in g reserve checke ch ecked d w ith th e d rag lin k taken ak en o ff (versi versio n s w ith au to m atically ad a d ju stin g steer ee rin g lim iter: er:d d o n o t tu rn to en d p o sitio n s w ith o u t th e d rag lin ks fitted )  j   yes   j   re-set

Play of input shaft bearing bearing arrange arrangem ment: Play in b ear ea rin g b u sh checke ch ecked d by r rat att tlin g at th e steer eeri in g w hee h eel l   j   yes   j   co rrecte cted Angular play Angular play and/or and/or stiff opera operation tion in joint betwee between n steering teering box and input shaft checked   j   yes   j   co rrecte cted 3

Chec hecking king the the compl omplet ete e stee teeri ring ng system tem for leakproofness:    

checked   j   yes   j   leakag ea kag e rem oved checked   j   yes   j   co rrecte cted

4

Tension ion of drive ive belt lt::

5

Chec hecking king the the hydr hydrau aulic lic func functioning tioning of pum pump and and ste teer ering ing gear gear

5.1

Fitting itting the ZF Ser ervot votes est power power ste steer ering ing tes teste ter r Note: C h eck th e p ressu essu re relief valve fo r cor co rrect p o sitio n in g . (p ressu essu re in d icati catio n o n th e cor co rresp espo o n d in g n am ep late) ate): : Attention to the differen Attention differenc ce: (see d escri escrip tio n in C h ap ter IV.) V.) Press Pressu u re relief ah a h ead o f t th h e ZF Servot Servotest est p po o w er steer ee rin g tester - Var V ari ian t ➲ Press Pressu u re relief aft aft o f th th e ZF Ser Se rvot vo test p po o w er steer ee rin g tester - Var V ari ian t ➳

In stru ct cti io n s o n D esig n , Fu Fun n ct cti io n in g , M ain ten enan ance ce an d In sp ecti ectio n

43

 

O rig in alf al fo r d u p licat cati in g (Pag Pa g e 2 )

In sp ecti ctio n rep o rt fo r ZF-S F-Servo ervoco com m steer ee rin g g ge ear ars s 5.2

 

Maxim Maximum um pum pump pre pres ssur ure e

Pressu re

b ar ar

5 .2 .1 For Fo r a steer ee rin g syst ystem to vari varian t ➲: p erm erm issi ssib le vari variati atio n fro m n o m in al p ress essu u re + 1 0 % 5 .2 .2 For Fo r a steer ee rin g syst ystem to vari varian t ➳ clo se th e sh u t-o ff valve o n ly u n til reach ea chi in g m axim u m p ressu essu re. p erm erm issi ssib le vari variati atio n fro m n o m in al p ress essu u re + 1 0 %

5.3

Chec hecking king the pum pump flow rate rate using the the ZF Ser ervot votes est power power ste steer ering ing tes teste ter: r: Id lin g sp e ee ed ap p ro x. 1 30 30 0 r.p .m .

r.p .m . Flo w rate

d m   3 /m in

Pressu re

b ar

Flo w rate

d m   3 /m in

Pressu re

b ar

LH

b ar

RH

b ar

 

5.4 Ste teer ering ing limite limiter r

5.5

Maxim Maximum um pr pres essur ure e of ste steer ering ing gear gear Th Thr ru st p ad ads s betw betw een th e lo ck sto p com p o n ent en ts. A llo w m axim u um m p ress essu re to be effective for 5 sec. m axim um at at idling spee peed. LH stop

bar bar

R H sto p b ar Perm issib le vari Perm variati atio n + 1 0 % if t th h e ZF Ser Se rvot vo test po w er steer ee rin g tester w a as s b u ilt in accord accord in g to p ara. ara. 5 .1 .2 o r no n o var vari iati atio n if t th h e ZF Ser Se rvot vo test po w er steeri eerin g tester w as b u ilt in accor acco rd in g to p ara. ara. 5 .1 .1 (C h apt ap ter IV ).

5.6 Checking king for for lea leakage kage oil: Thrust Thr ust pad s bet b etw w een the lock sto p com p on ents ents. A llow m axim um p ressu essu re to b e eff effecti ective fo r 5 sec. m axi a xim u m at id lin g sp eed . LH sto p

d m   3 /m in

Set to m axim u m p ressu re m in u s 3 0 b ar

R H sto p

d m   3 /m in

Leakag e o il w ith flo w rate ate redu ed u ced to 2 d m   3 /m in

LH sto p

d m   3 /m in

R H sto p

d m   3 /m in

If p ressur ssure relief is to var varian t ➳

 

5.7 Valve Valve re retu turn rn motion otion O il p pr ressu re d ro p to id le p ressu re

ch e ec cked   j   yes   j   n o

5.8 Play lay at the the stee teering ring whee wheel: (ro ad w h eel ee ls lo cke cked d .) To tal travel o n steer ee rin g w h eel ee l circum feren eren ce at a p ressu re rise o f 1 b ar co m p ared to id le p ressu re 6

Filt ilte er changed:

7

Oil le leve vell ch check an and ble lee edin ing g:

8

Test drive

j   yes   j   no

     

mm

j   yes   j   no j   yes   j   no

Rem arks:   ..................................................................................... C h ecked b y (n am e):

D ate: