4.2 - Automatic Transmission [OCR]
Short Description
Saab 900 OG900 Service Manual...
Description
SERVICE MANUAL
024 Technical data 104 Special tools General, road testing and fault
Saab 900
440 diaqnosis 442
Removal, fitting
444 Transmission control 472 Dismantling, assembly
SERVICE MANUAL 4:2 Automatic transmission M1986-92
...---:.
Differential and pinion/crown wheel
473 gear
475 Universal joints
· Units The basic and derived units used throughout the Service Manual are in accordance with the SI system. (Systeme International d'Unites) For users not familiar with the SI units, some non-Continentpl units are given in brackets after the respective SI unit. The following symbols and abbreviations are used:
51 unit
Equivalent unit and symbol
Millimeter (mm) Kilograme (kg) Newton (N) Newtonmeter (Nm) Atmosphere (bar)
inch (in) pound (Ib) pound-force (Ibf) foot pound (ft Ib) pound-force per square inch (Ibf/in 2 ) (Also abbreviated: psi) US liquid quart (Iiq qt) (Also abbreviated: qts) US gallon (USgal) °Fahrenheit eF)
Liter (I)
°Celcius eC)
Conversion factors 1 in = 25.4 mm t Ib = 0.45 kg 1'lbf = 4.45 N 1 Ibf ft = 1.36 Nm 1 psi = 0.07 bar 1 US Iiq qt = 0.83 UKqt
of
=
°C x 9/5
+
32
1 mm = 0.039 in 1 kg = 2.201b 1 N = 0.23 Ibf 1 Nm = 0.74 Ibf ft 1 bar = 14.5 Ibf/in 2 1 I = 1.05 liq qt 1 USgal = 0.83 UKgal °C = (OF - 32) x 5/9
Market codes The codes refer to market specifications AT AU BE CA
CH DE DK ES EU FE FI
FR
Austria Australia Belgium Canada Switzerland Germany Denmark Spain Europe Far East Finland France
GB
GR IS IT
JP ME
NL NO SE US UC
© Saab Automobile AB 1992 Production: Technical Publications, Saab Automobile AB, Trollhattan, Sweden
Great Britain Greece Iceland Italy Japan Middle East Netherlands Norway Sweden USA US California
"
Technical data
024-1
Technical data Previously there were two types of automatic transmission: the earlier model 35 and later the strengthened and modernized model 37, which was introduced on model year 1979 cars. The following description concerns model 37. When carrying out any work on model.35 automatic transmission units, refer to Service Manual 4:2 M79-85 (part No. 32 8906).
Identification of torque converters for automatic transmission units The identification number is stamped on the torque converter as shown. Model
Type
Torque converter
37
008,009,011,013,014, 015,016,017
225K
Identification number 3713
Note: All model 37 transmissions have 8 holes in the mounting ring.
ID number
Saab 900
024-2
Technical data
Type designation, model year 1984 and later GA
3
3
4
09
1j
GM = Manual gearbox J GA = Automatic transmission - - - - - - - - - ' Transmission adaptation . Number of forward speeds - - - - - - - - - - - - - ' 3 = 3-speed 4 = 4-speed 5 = 5-speed Primary gear ratio - - - - - - - - - - - - - - - - - ' Development stage, variant - - - - - - - - - - - - - - - '
Gear ratio designations 3
4
Number of teeth in/out
40/37
41/36
Ratio
0.93
0.88
Primary gear
Automatic transmission Borg Warner, type 37
Manufacturer and type Fluid capacity, automatic transmission
Iitres (qts)
Type of fluid Fluid capacity, lubricated-for-Iife final drive
M2C.33G or M2C.33F according to Ford specification litres (qts)
1.25 (1.31) Motor oil (mineral oil) 10W/30 or 10Wj'Tv '
Type Weight
8.0 (8.40). When changing the fluid, only abc 3 litres can be drained via the drain plug.
kg (Ib)
Saab900
84 (185.18)
Technical data
024-3
Ratios Type 008 Standard Torque converter ratio Primary gear ratio
.
0.97
009 Turbo, 011 Turbo Turbo 16 US EU,SE
013 Standard
014 Turbo 16 cat
0.92
0.88
3.67
3.89
3.89
9:33
9:35
9:35
012 Standard 2.38:1-1 :1
0.93
0.88
0.92
1st gear
2.39:1
2nd gear
1.45: 1 1:1
3rd gear
2.09:1
Reverse gear Final drive ,.
Number of teeth
Type 015 i16
016 Turbo 16
017 i16,i162.31
0.93
0.88
0.88
Torque converter ratio Primary gear ratio 1st gear
2.39:1
2nd gear
1.45:1
3rd gear
1:1 2.09:1
Reverse gear Final drive Number of teeth
3.89 9:35
3.89
3.89
9:35
9:35
Saab 900
024-4
Technical data
Ratios Model
Year
1986
1992
Overall ratio 1
2
3
Reverse
39:38 0.97
9:33 3.67
8.54
5.18
3.57
7.47
900 Turbo, not US (011 )
GA43707 (011)
41 :36 0.88
9:33 3.67
7.69
4.67
3.22
6.73
Turbo 16 US (009)
GA53307 (009)
40:37 0.93
9:33 3.67
8.11
4.92
3.39
7.09
900c, i, i16, S16
GA33207 (008)
39:38 0.97
9:33 3.67
8.54
5.15
3.57
7.47
900 Turbo 16
GA53307 (009)
40:37 0.93
9:33 3.67
8.11
4.92
3.39
7.09
Turbo 8, cars with sports pack
GA43707 (011)
41 :36 0.88
9:33 3.67
7.69
4.67
3.22
6.73
900c, i, i16, S16
GA33207 (008)
39:38 0.97
9:33 3.67
8.54
5.15
3.57
7
900 Turbo 16 cat
GA53307 (009)
40:37 0.93
9:33 3.67
8.11
4.92
3.39
7.09
Turbo 8, cars with sports pack
GA43707 (011)
41 :36 0.88
9:33 3.67
7.69
4.67
3.22
6.73
900, i, i16, S16
GA33308 (013)
40:37 0.92
9:35 3.89
8.61
5.22
3.60
7.53
900 Turbo 16 cat
GA53408 (014)
41 :36 0.88
9:35 3.89
8.17
4.95
3.41
7.15
900i, i16, S16
GA33308 (013)
40:37 0.92
9:35 3.89
8.61
5.22
3.60
7.53
900 Turbo 16 cat
GA53408 (014)
41 :36 0.88
9:35 3.89
8.17
4.95
3.41
7.15
900, i16,
GA33309 (015)
40:37 0.93
9:35 3.89
8.61
5.22
3.60
7.53
900 Turbo 16
GA53409 (016)
41 :36 0.88
9:35 3.89
8.17
4.95
3.41
7.15
900i 16, 900i 16-2.1 I
GA33409 (017)
41 :36 0.88
9:35 3.89
8.17
4.95
3.41
7.1/
900 Turbo 16
GA53409 (016)
41 :36 0.88
9.35 3.89
8.17
4.95
3.41
7.14
.-
1991
Final drive
GA33207 (008)
1988
1990
Primary gear
900 GL, i, 900 US, 900 S (008)
1987
1989
Transmission number
Saab 900
A7
Technical data
024-5
Road speed Year
1986
1987
1988
Model
Transmission number
Tyres
1
2
3
900 GL
GA33207
2)
13.4
22.1
32.2
900 i
GA33207
7)
13.3
21.9
31.8
900 US, 900S GA33207 (008)
9)
13.2
21.8
31.6
900 Turbo, not GA43707 (011) US
9)
14.7
24.1
35.0
900 Turbo 16S GA53307 (009) US
10)
13.9
23.0
33.5
Reverse
900e, i, i16, S16
GA33207 (008)
3)
13.5
22.2
32.2
15.4
900e, i, i16, S16
GA33207 (008)
7)
13.3 ,.
21.9
31.8
15.2
900e, i, i16, S16
GA33207 (008)
9)
13.2
21.8
31.6
15.1
900 Turbo 16 GA53307 (009)
10)
13.9
22.9
33.3
15.9
900 Turbo 8
GA43707 (011)
8)
14.8
24.3
35.2
16.1
Cars with sports pack
GA43707 (011)
10)
14.7
24.1
35.0
16.7
900e, i, i16, S16
GA33207 (008)
3)
13.5
22.2
32.2
15.4
900e, i, i16, S16
GA33207 (008)
7)
13.3
21.9
31.8
15.2
900e, i, i 16, S16
GA33207 (008)
9)
13.2
21.8
31.6
15.1
10)
13.9
22.9
33.3
15.9
900 Turbo 16 GA53307 (009) eat
1989
Road speed, km/h per 1,000 rpm
900 Turbo 8
GA43707 (011)
8)
14.8
24.3
35.2
16.1
Cars with sports paek
GA43707 (011)
10)
14.7
24.1
35.0
16.7
900i, i16, S16 GA33308 (013)
3)
13.4
22.0
32.0
15.3
900i, i16, S16 GA33308 (013)
7) or 8)
13.2
21.8
31.5
15.1
900i, i16, S16 GA33308 (013)
9)
13.1
21.6
31.3
15.0
900 Turbo 16 GA53408 (014) eat
7) or 8)
13.9
22.9
33.2
15.9
900 Turbo 16 GA53408 (014) eat
10)
13.8
22.8
33.0
15.8
1) 165 SR 15: Dyn. rolling radius 312 mm
6) 185/65 SR 15: Dyn. rolling radius 301 mm
2) 175/70 SR15: Dyn. rolling radius 305 mm
7) 185/65 TR15: Dyn. rolling radius 301 mm
3) 175/70 TR15: Dyn. rolling radius 305 mm
8) 185/65 HR 15: Dyn. rolling radius 301 mm
4) 175/70 HR15: Dyn. rolling radius 305 mm
9) 195/60 HR 15: Dyn. rolling radius 299 mm
5) 180/65 HR390: Dyn. rolling radius 297 mm
10) 195/60 VR15: Dyn. rolling radius 299 mm
Saab 900
024-6
Year
1990
1991
1992
Technical data
Model
Transmission number
Road speed, km/h per 1,000 rpm
Tyres
900i, i16, 816 GA33308 (013)
1
2
3
Reverse
3)
13.4
22.0
32.0
15.3
900i16,816
GA33308 (013)
7) or 8)
13.2
21.8
31.5
15.1
900i16,816
GA33308 (013)
9)
13.1
21.6
31.3
15.0
900 Turbo 16 GA53408 (014) cat
8)
13.9
22.9
33.2
15.9
900 Turbo 16 GA53408 (014) cat
10)
13.8
22.8
33.0
15.8
900, i16
GA33309 (015)
3)
13.4
22.0
32.0
15.3
900, i16
GA33309 (015)
8)
13.2
21.8
31.5
15.1
900, i16
GA33309 (015)
10)
13.1
21.6
31.3
15.0
900 Turbo 16 GA53409 (016)
8)
13.9
22.9
33.2
15.9
900 Turbo 16 GA53409 (016)
10)
13.8
22.8
33.0
15.8
GA33409 (017)
7)
13.9
22.9
33.2
15.9
900S; GA53409 (016) 900 Turbo 16
8)
13.9
22.9
33.2
15.9
900 Turbo 16 GA53409 (016)
10)
13.8
22.8
33.0
15.8
900; 16;
i 16-2.1 I
I'
I'
II
I
!
i ,
1, , 1. ,,..
1) 165 8R15: Dyn.rolling radius 312 mm 2) 175/70 8R15: Dyn. rolling radius 305 mm 3) 175/70 TR15: Dyn. rolling radius 305 mm 4) 175/70 HR15: Dyn. rolling radius 305 mm 5) 180/65 HR390: Dyn. rolling radius 297 mm 6) 186/65 SR 15: Dyn. rolling radius 301 mm 7) 185/65 TR15: Dyn. rolling radius 301 mm 8) 185/65 HR15: Dyn. rolling radius 301 mm
I
i "
..
9) 195/60 HR 15: Dyn. rolling radius 299 mm 10) 195/60 VR15: Dyn. rolling radius 299 mm
Saab 900
Technical data
Shift speeds ,
Upshifts
Downshifts
1st-2nd
2nd-3rd
3rd-2nd
3rd-1 st
Light throttle*
13-25
18-29
***
1-18
"Kick-down"**
62-71
107-119
90-105
41-55
Light throttle*
13-25
18-29
***
1-18
"Kick-down"**
61-71
107-119
90-105
41-55
Light throttle*
15-27
20-32
***
1-19
"Kick-down"**
69-78
114-127
95-111
47-62
Light throttle*
15-29
20-32
***
1-18
"Kick-down"**
67-78
119-135
100-118
47-61
Light throttle*
13-25
18-29
***
1-18
"Kick-down"**
62-71
107-119
90-105
41-55
Light throttle*
14-27
19-30
***
1-17
"Kick-down"**
66-77
112-127
94-111
43-58
Light throttle*
14-27
19-30
***
1-17
"Kick-down"**
70-81
115-130
98-115
43-58
Stall speed
Type
2000-2400 rpm
M84,006, Standard
2000-2300 rpm
M85,008, Standard
',2400-2700 rpm at 0.40 bar (5.8 psi) charging pressure = basic charging pressure
M85,009, Turbo APC!Turbo 16 US
2250-2550 rpm at 0.30 M85,011, bar (4.3 psi) charging Turbo 8, EU, pressure = basic charg- SE ing pressure
:
*
Light throttle shifting. Start from stationary with lightest possible throttle and note road speed when shifts occur.
**
Kick-down. Accelerator pressed to floor.
*** Rolling to rest. Release the accelerator and let the car roll along until it stops by itself. Note the speed at which downshifting occurs.
Saab 900
2000-2300 rpm
M841/2, 012, Standard
2000-2300 rpm
M89,013, Standard
2400-2700 rpm at 0.40 M89,014, bar (5.8 psi) charging Turbo pressure = basic charging pressu re
024-7
024-8
Technical data
Tightening torque Brake bands Front brake band adjusting;screw
Nm (Ibfft)
1.3 (0.96)
Front brake band adjusting screw locknut
Nm (Ibf ft)
20-27 (15-20)
Rear brake band adjusting screw
Nm (Ibf ft)
14 (10)
Nm (Ibf ft)
39-53 (29-39)
Torque converter to drive plate (8)
Nm (Ibf ft)
33-39 (24-29)
Chain cover to torque converter housing (12)
Nm (Ibf ft)
14-21 (10-15)
Slacken rear brake band (1 - 1 1/4 turns) Front brake band adjusting screw locknut
Transmission
Transmission casing to torque converter housing (10)
Nm (Ibf ft)
14-21 (10-15)
Sprocket to turbine shaft
Nm (Ibf ft)
88-102 (65-75)
Sprocket to input shaft in gearbox
Nm (Ibf ft)
136 (100)
Suppurt in transmission casing (3)
Nm (Ibf ft)
14-25 (10-18)
Selector rod side cover to transmission casing;
Nm (Ibf ft)
11 (8)
Oil sump to transmission casing
Nm (Ibf ft)
11 (8)
Valve budy cover to torque converter housing
Nm (Ibf ft)
11 (8)
Drain plug in oil"Ran
Nm (Ibf ft)
5-8 (4-6)
EnginEf.'sump drain plug
Nm (Ibf ft)
35-39 (26-29)
l
i'
I
Saab 900
Technical data Final drive
Seal housing - pinion bearing housing (2)
Nm (Ibf ft)
2.31-3.40 (1. 7-2.5)
Pinion shaft nui
Nm (Ibf ft)
215-264 (158-195)
New bearings (lightly oiled)
Nm (Ibf ft)
2.2-2.7 (1 :6-2.0)
Old bearings (lightly oiled)
Nm (Ibf ft)
0.9-1.5 (0.7-1.2)
Seal housing to pinion bearing (2)
Nm (Ibf ft)
8-12 (6-9)
Pinion bearing to transmission casing
Nm (Ibf ft)
26~33 (19-24)
Pinion bearing pre-load (torque required to rotate pinion shaft measured with a spring balance): 34-58 N {7.8-13.4 Ibf} {"old" bearings 19-30 N (4.4-6.9 Ibf)
'~.
Crown wheel screws (final drive 9:35) (12)
Nm (Ibf ft)
80-100'(59-74)
M10.x.L25
(final drive 9:33) (12)
Nm (Ibf ft)
80-100 (59-74)
M10 x 1.25
New bearings (lightly oiled)
Nm (Ibf ft)
1.8-2.8 (1.3-2.1)
Original bearings in use for over 2000 km
Nm (Ibf ft)
0.8-1.3 (0.6-1.0)
Differential bearing seats (2 x 6)
Nm (Ibf ft)
20-25 (15-18)
Filler plugs
Nm (Ibf ft)
39-59 (29-44)
Drain plugs
Nm (Ibf ft)
39-59 (29-44)
5/16"-18-2 UNC (5) M6x1.0
Nm (Ibf ft) Nm (Ibf ft) Nm (Ibf ft)
2.5-3.9 (1.8-2.9) 23-29 (17-21) 6.1-8.8 (4.5-6.5)
Pump to torque converter housing (3)
Nm (Ibf ft)
18-25 (13-18)
Governor valve inspection cover to transmission casing (2)
Nm (Ibf ft)
7-11 (5-S)
Governor valve to counterweight on pinion shaft (2)
Nm (Ibf ft)
5-S (4-6)
(2)
Nm (Ibf ft)
2-5 (1.5-3.7)
Governor mounting - output shaft
Nm (Ibf ft)
5.5-S.0 (4-6)
Differential support bearing Rolling resistance
Oil pump
Pump cover to pump housing
Governor valve
Cover plate to governor valve body
Saab 900
024-9
024-10
Technical data
Valve body
-
Upper part to valve body (8)
Nm (Ibf ft)
2-3 (1.5-2.2)
Manual valve lever bracket to valve body (4)
Nm (Ibf ft)
2-3 (1.5-2.2)
Oil pump tube connecting plate to valve body (8)
Nm (Ibf ft)
2-3 (1.5-2.2)
End plate, primary and secondary valves, to valve body (3)
Nm (Ibf ft)
2-3 (1.5-2.2)
Rear upper end plate to shift valve body (3)
Nm (Ibf ft)
2-3 (1.5-2.2)
Front upper end plate to shift valve body (3)
Nm (Ibf ft)
2-3 (1.5-2.2)
Kick-down cam bracket to valve body (3)
Nm (Ibf ft)
2-4 (1.5-2.9)
Valve body to transmission casing (3)
Nm (Ibf ft)
6-12 (4.4-9.0)
Kick-down throttle cable connection to transmission casing
Nm (Ibf ft)
11-14 (8-10)
Drain valve (3)
Nm (Ibf ft)
7-11 (5-8)
Drain tube in valve
Nm (Ibf ft)
4.7-6.1 (3.5-4.5)
Oil cooler nipple (2)
Nm (Ibf ft)
7-10 (5-7)
Nut, oil cooler connection (2)
Nm (Ibf ft)
13-16 (9.6-12)
Oil pressure gauge plug
Nm (Ibf ft)
5-7 (4-5)
Starter switch locknut
Nm (Ibf ft)
5-8 (4-6)
Miscellaneous
1.
Saab 900
-
Special tools
104-1
Special tools Certain tools may also be shown in other groups.
7874878 (A2) Floor stand, fixed
83 90 478 (A2) Axle for floor stand
78 60 802 (A2) Oil pan for floor stand
83 90 460 (A2) Holder, gearbox
S 4644
83 92 409 (A1) Lifting tackle for power unit
87 90 370 (A1) Key for special nut, gear lever housing Saab 900
104-2
Special tools
-
83 93 209 (A 1) Spacer tool for relieving load on spring assembly when removing the power unit, etc.
87 90 776 (A1) Puller for inner drive shaft with bearing cap
S 4663 ~\ I.
: I.
I:
'"
87 90 636 (A2) Fixture for removing and fitting of bearing on pinion 87 90 669 Puller ring 9:35 87 91 097 Puller ring 9:33 87 90 982 Fitting ring for pinion bearing
87 90 461 (A2) Fitting of front pinion bearing and bearing in torque can' housing
. I
S 4/155
87 91 113 (A1) Socket for pinion shaft nut
83 90 189 (A2)
Saab 900
Drift, used with washer 87 90 ! removing the front pinion t race and rear pinion bearing r; gether with ring 8790537. Als for manual gearbox ? .... r1 s swivel member
Special tools
83 90 155 (A2) Set of tools for measuring pinion clearance
7840 ..622 .,.
104-3
Dial gauge
,
)r
19
78 41 141 (A2)
Sleeve, for pressing in ball bearing, differential bearing cap
78 41 067 (A2) Sleeve for removing ball bearing, differential bearing cap, and fitting of bearing cap with ball bearing to inner driver.
87 90 818 (A3)
Driver, for measurement of differential bearing torque
83 90 270 (A1) Sliding hammer
)-
id 19
87 91 337
As above, but suitable for a heavier differential shaft
Saab 9000
104-4
Special tools
8791 055 (A1) Complete pressure gauge set 87 91 071 Hose with connecting nipples 87 91 089 Connecting piece with non-return valves
87 90 727 (A2)
87 90 081 (A2) Sleeve for removing and fitting of spring, rear clutch
8790693 (A2) Sleeve for fitting of piston, real
_I
I~_
Sleeve for fitting of piston, front clutch
87 90 115 (A1) Sleeve, for adjustment of rea band
4
' - - - - - - - - - : - - : 693 -_5
87 90 107 (A2)
Fixture set for measuring backlash in final drive an float of input shaft
Saab 9000
Special tools
104-5
r~r--------D 1d
ch
Ike
t
87 90 875 Spanner for adjustment of rear brake band
8790)31 (A1) Torque wrench
8790 149 (A1) Screwdriver, adapter
87 90 156 (A1) Sleeve for adjustment of front brake band
87 90 180 (A2) Pliers
87 91 378
Saab9000
Ring for removal and fitting of outer race, rear pinion bearing
104-6
8791 014
Special tools
Locating studs, pinion bearing housing, set of four (M10 thread)
87 90 230 (A2) Holding tool, primary gear
I'
jl:
I'
j
1:
I, i
I
j',
I:
J
1
;:)1 1 8790 248 (A2),Gentring sleeve for oil pump
.
~
87 90 255 (A2) Transport support for torque converter
;
@ S 4709
'----_!_I 87 91 048 Weight for rear clutch measurement
1_ _
87 90 487 (A2) Sleeve for differential housin~ bearing
Saab 900
Special tools
S
78 41 141
104-7
41051
Drift for removal of front pinion bearing race
87 90.958 (A2) ;Bolt for removal cof output shaft, ring-gear
)-----~:......~.
89 95 177
Dolly for removal of differential bearing
.~
87 90 883 (A1) Allen key, for adjustment of gear selector positions
~\
~
/
-----~ Sl7J2
87 90 974 (A2)
Washer, for removal of front pinion bearing race. For use with drift 83 90 189
83 90 990
Saab 900
Drift for fitting of seals, pinion shaft in pinion bearing housing. Used with fixture 87 90 636 and fitting ring 87 90 925.
104-8
Special tools
87 90 941 (A2)
Drift for fitting of oil pump seal
87 90 438
Locating stud for fitting of oil
,-
87 91 006 (A2)
Cone for fitting pinion shaft into pinion bearing housing (to protect seals)
4 _ 5 1627
87 91 352
89 95 607
Tool for fitting and removal spring for rear servo lever
_I IL-_
Drive ring for fitting the pinion bearing housing
87 91 360
Saab 900
Slide hammer for removin( delivery pipe
Special tools
iP
104-9
87 90 800
Drift for pressing the seal into the differential bearing cap and pressing in the output shaft
87 91 345
Tool for fitting and removal of rear servo spring
83 90 114
Sleeve for removal of pinion bearing housing
83 90 148
Sleeve for removal of pinion bearing housing
8791329
Spacer for adjustment of front brake band, 7.87 mm
Saab 900
General, road testing and fault diagnosis
440-1
General, road testing and fault diagnosis Selector lever positions Torque converter .. Chain drive. . . . . Planetary gear train Clutches . . . . Brake bands . . . . One-way clutch. . . Mechanical transmission Hydraulic system. Pump . The automatic transmission element hydrokinetic torque draulically operated gearbox for three forward speeds and
· · · ·
440-1 440-2 440-3 440-3 440-3 440-5 440-5 440-5 440-7 · 440-7
Governor . . . 440-7 Control system. . . . . . . . . . . . . . . 440-8 Valves . · 440-20 Driving instructions. · 440-28 Towing . · 440-29 Maintenance . · 440-30 Oil cooler, cars with automatic transm. · 440-31 Tracing faults in the torque converter. · 440-33 Checking the stall speed . · 440-33
consists of a threeconverter and a hywith planetary gears reverse.
Selector lever positions Position 0 This position is provided for all normal driving. It is used to move the car from rest in 1st gear and shifts up and down through the gears automatically.
Position 2 This position is provided for use when only the first two gears are required and shifts up and down automatically between 1st and 2nd gears. Driving in 3rd gear is not possible in this position.
Automatic transmission
Position 2 must not be selected at speeds higher than 90 km/h as it could lead to over-revving of the engine.
Position 1 No upshifting takes place in this position. If the selector lever is moved from position D to position 1 at high speeds, the gearbox shifts down automatically to 2nd gear and then, when the car has decelerated to a certain speed, down to 1st gear. Position 1 must not be selected at speeds above 90 km/h, however.
Saab 900
440-2
General, road testing and fault diagnosis
Torque converter The use of a hydraulic torque converter in conjunction with a three-speed automatic gearbox provides 'a means of obtaining smooth application of engine power to the driven wheels and additional engine torque, The torque converter also provides extreme low speed flexibility when the gearbox is in 3rd gear and, due to the higher engine torque produced, it provides good acceleration from very low road speeds without necessitating a downshift in the gearbox. Torque multiplication in the converter is steplessly variable between the ratios of 2: 1 and 1: 1. The speed range within which torque multiplication takes place is also variable and depends on the position of the accelerator.
Torque converter
The torque converter that is used in conjunction with the gearbox consists of an impeller connected to the engine crankshaft, a turbine connected to the input shaft of the gearbox, and a stator mounted on a one-way clutch with a fixed hub which is connected to the torque converter housing. The impeller is driven by the engine and converts its power into hydrokinetic energy. The fluid flows from the impeller vanes to the turbine vanes and returns to the impeller through the stator vanes. The curvature of the different vanes is so designed that when a speed differential exists between the impeller and the turbine, the angle of the fluid flow from the turbine is changed by the stator vanes in such a way that the discharge of fluid from the stator assists in driving the impeller.
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1 Torque converter - principle of operation
Torque multiplication occurs under these conditions and varies from about 2: 1 when the turbine is locked to 1:1. Torque multiplication of about 2: 1 is obtained when the car is at a standstill with the engine running at full throttle and with the gear selector lever in any of the drive positions. A torque of 1:1 is obtained when the turbine rotates at a speed approximating 9O%of the impeller speed. When this speed differential between the impeller and turbine is achieved, the fluid flow angle from the turbine is such that the stator is driven in the same direction as the turbine and the impeller. Under these circumstances, the torque converter operates as a fluid fiywheei or coupling and there is no torque multiplication.
Saab 900
1
Impeller
2 Turbine 3 Stator
1
General, road testing and fault diagnosis
Chain drive Power is transmitted by means of a chain from the turbine shaft of the torque converter to the input shaft of the transmission.
Planetary gear train The planetary gear train consists of two sets of planet gears, a planet carrier and a ring gear. All gears have helical involute teeth. Power enters the gear train via the sun wheel. In all forward gears, power enters through the forward sun wheel. In reverse, power enters through the reverse sun wheel. Power leaves the gear train via the ring gear. in reverse, the planet carrier is braked, causing the ring gear to rotate in the opposite direction to the sun wheel. In forward gears, both sets of planet gears are used to cause the ring gear to rotate in the same direction as the sun wheel. The planet carrier holds the planet gears in their correct positions relative to each other and to the sun wheel. At the same time, it also serves as a reaction member under certain conditions. The various mechanical ratios are obtained by the engagement of hydraulically operated multi-disc clutches and brake bands.
Clutches Multi-disc clutches operated by hydraulic pistons connect the torque converter to the gearbox. In all forward gears the front clutch connects the torque converter to the rear sun wheel. In reverse gear the rear clutch connects the torque converter to the front sun wheel.
Saab 900
440-3
General, road testing and fault diagnosis
440-4
1
2
3
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465
Automatic transmission, principle of operation
1 2 3 4 5 6 7
Torque converter Front clutch Rear clutch Front brake band Rear brake band One-way clutch Governor
AppHcation of brake bands and clutches for the different selectot" positrons
I
Selector lever position
Gear
Applied
Driving
Held
1
1st
Front clutch Rear brake band, one-way clutch
Rear sun wheel
Planet carrier
D and 2
1st
Front clutch One-way clutch
Rear sun wheel
Planet carrier
D and 2
2nd
Front clutch Front brake band
Rear sun wheel
Front sun wheE
D
3rd
Front clutch Rear clutch
IFront and rear sun wheels
R
Reverse
Rear clutch Rear brake band
Front sun wheel
Saab 900
Planet carrier
General, road testing and fault diagnosis
Brake bands Brake bands, operated by hydraulic servos, hold units of the planetary gear train stationary to increase torque and bring about a reduction in output speed. In selector lever position 1, the rear brake band holds the planet carrier stationary and provides the 1st gear ratio of 2.39:1 or, in reverse gear, a ratio of 2.09:1. The front brake band holds the front sun wheel stationary to provide the 2nd gear ratio of 1.45:1.
One-way clutch In selector position D, a one-way clutch is used instead of the rear brake band to provide a 1st gear ratio of 2.39: 1. This one-way clutch allows the car to freewheel in 1st gear and makes for smooth downshifting from 2nd to 1st.
Mechanical power transmission 1st gear ("1" selected) The front clutch is applied, connecting the torque converter to the rear sun wheel. The rear brake band is applied, holding the planet carrier stationary so that engine braking is obtained. A ratio of 2.39:1 results. The front sun wheel rotates freely in the opposite direction to the rear sun wheel.
Mechanical power transmission Position 1, 1st gear
1st gear ("0" or "2" selected) The front clutch is applied, connecting the torque converter to the rear sun wheel. The one-way clutch is in operation, preventing the planet carrier from rotating anticlockwise. A ratio of 2.39:1 results. When the car is coasting "faster than the engine", the one-way clutch over-runs and the gearbox freewheels.
Mechanical power transmission Position 0 or 2, 1st gear
Saab 900
440-5
440-6
General, road testing and fault diagnosis
2nd gear ("0" or "2" selected) The front clutch is applied in this case also, connecting the torque converter to the rear sun wheel. The front brake band is applied, holding the front sun wheel stationary. A ratio of 1.45:1 results.
Mechanical power transmission Position 0 or 2, 2nd gear
3rd gear ("0" selected) Here again the front clutch is applied, connecting the torque converter to the rear sun wheel. The rear clutch is applied, connecting the torque converter to the front sun wheel also. Both sun wheels are accordingly locked together and the planetary gear train rotates as a single unit, providing a ratio of 1:1.
Mechanical power transmission Position 0, 3rd gear
Neutral and Park positions In the neutral and park positions the front and rear clutches are released and no power is transmitted from the torque converter to the planetary gear train. The front and rear brake bands are also released.
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Reverse gear ("R" selected) The rear clutch is applied, connecting the torque converter to the front sun wheel. The rear brake band is applied, holding the planet carrier stationary. The planetary gear train provides a ratio of 2.09:1 in the reverse direction.
Mechanical power transmission Position R, reverse gear
Saab 900
General, road testing and fault diagnosis
Hydraulic system The hydraulic system contains an internal/external gear type pump which picks up fluid from the oil pan through a strainer. Automatic control is provided by a centrifugally operated hydraulic governor on the transmission pinion shaft. This governor works in conjunction with valves in the valve body assembly located in the transmission. These valves regulate the fluid pressure and direct it to the appropriate units in the transmission.
Pump The pump, driven by the torque converter, is in operation whenever the engine is running. Through the primary and secondary regulator valves, this pump supplies the transmission with fluid.
Governor The governor, revolving with the output shaft, is basically a pressure regulating valve which reduces the line pressure to a value that varies with the speed of the output shaft (Le. the car). This variable pressure, known as governor pressure, is utilized in the control system for shifting up and down between 1st and 2nd gears and between 2nd and 3rd gears. Rotation of the governor at low speeds causes the governor weight and valve to be affected by centrifugal force. This outward force is opposed by an opposite and equal hydraulic force produce by pressure acting on the regulating area of the governor valve. The governor valve is a regulating valve and will attempt to maintain equilibrium. Governor pressure will rise in proportion to the increase in centrifugal force caused by higher output shaft speed.
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As the speed increases, the governor weight moves outwards by centrifugal force to a stop in the governor body past which it cannot move. At this point, a spring located between the weight and the governor valve comes into operation. The constant force of this spring then combines with the centrifugal force of the governor valve and the sum of these forces is opposed by the governor pressure, rendering this pressure less sensitive to variations in the speed of the output shaft. Accordingly, the governor provides two distinct phases of regulation, the first being used for precise control of the shifting points at low speeds.
Saab 900
440-7
440-8
General, road testing and fault diagnosis
Control system The control system utilizes three basic types of valve: regulating valves, shuttle valves and a manual valve. System and torque converter pressure is controlled by the primary and secondary regulating valves. The primary regulating valve adapts system pressure in relation to throttle pressure, which acts on the spring end of the regulating valve, and also in relation to modulated throttle pressure acting on the opposite end of the valve.
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Shift control is provided by 1st-2nd and 2nd-3rd shift valves which are controlled by governor and throttle pressure, the system pressure acting upon the valve areas of different size to provide the shift pulses. Manual control is provided by the selector valve which, depending on the position of the selector lever, directs fluid to or from the clutch and brake servo pistons.
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34
5
6
Principle of operation, front servo 1 2 3 4 5 6 7
For ease of reference, all hydraulic circuits are identified by numbers. See the table of hydraulic circuits on page 270f this section.
Brake band Damper Servo piston Cap Adjusting screw Rocker arm Push rod _
7
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! Principle of operation, rear servo 1 2 3 4 5 6 7 8
Saab 900
Brake band Servo piston, reverse gear Accumulator Push rod Lever Rocker arm Adjusting screw Locknut
General, road testing and fault diagnosis
Operation in position N With the engine running, the primary regulating valve regulates system pressure (1) which is directed to the selector valve and throttle valve. It also allows fluid to reach the secondary regulating valve. The secondary regulating valve regulates the pressure to the torque converter and lubrication of the front end of the planetary gear train (21). Identical pressure (23) is directed to the rear end of the gear train. The valve returns excess fluid (24) to the oil pan.
Operation in position P An internal linkage from the selector valve detent lever engages the parking pawl with teeth formed on the driven shaft ring gear. With the engine running, the operation of the hydraulic system is identical to that in position N, except that the selector valve directs the system pressure (6) to the rear servo (13). This is due to the design of the selector slide, and application of the rear servo or brake band fulfils no function in this selector position.
Operation in position R Pressure control of the pump is the same as in position P or N but, depending on accelerator pedal depression, throttle pressure (9) is directed to the spring end of the primary regulating valve, thus increasing the system pressure (1) in accordance with the torque capacity requirements. The selector valve directs system pressure (6) through the 1st2nd gear shift valve to the rear servo (13) and system pressure (7) through the 2nd-3rd gear shift valve to the rear servo and front servo release side (15). Owing to the absence of governor pressure, the shift valves and flow restrictor perform no function in this selector position. The fluid passages (13) and (15) of other selector valve positions are utilized in position R to simplify the design of the hydraulic circuits.
Saab 900
440-9
440-10
General, road testing and fault diagnosis
Operation in position 0 or 2 - 1st gear 1
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Pressure control of the pump is the same as in position R but with the throttle vale in the full throttle position as illustrated. Throttle pressure (9), controlled by the modulator valve plunger (8), then acts on the primary regulating valve against the throttle pressure (9), thus modulating the system pressure in the interests of gear- shifting smoothness in all driving conditions. The selector valve directs the system pressure (5) to the front clutch, the governor, and the 1st-2nd gear shift valve for the subsequent upshift from 1st to 2nd gear. System pressure (3) is directed to the 2nd-3rd gear shift valve for the subsequent upshift from 2nd to 3rd gear. The front clutch applied in conjunction with the one-way clutch permits the car to move off from rest in 1st gear. The hydraulic circuit for position 2 (1 st gear) is the same as for position D (1 st gear) except that the system pressure (3) is prevented from reaching the 2nd-3rd gear shift valve by a stop or flange on the selector valve.
Operation in position 0 or 2 - 2nd gear
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The primary regulating valve controls the pressure from the pump output. Throttle pressure (8-9) acts on the primary regulating valve in the same way as in position D - 1st gear.
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Shift control is provided by the 1st-2nd shift valve moving to the left, see Fig., under the influence of governor pressure (2), which is opposed by the spring force and throttle pressure (10). This permits system pressure (5) to reach the application side of the front servo (19). The front brake band is thus applied, in conjunction with the front clutch, to provide 2nd gear. With the kick-down valve in the position shown in the Fig., throttle pressure (11) will act on the 1st-2nd and 2nd-3rd shift valves, thus further delaying the upshift (or providing a 3rd-2nd or 2nd-1 st downshift at speeds giving very little governor pressure (2). The hydraulic circuit for position 2 (2nd gear) is the same as for position D (2nd gear) except that the line pressure (3) is prevented from reaching the 2nd-3rd shift valve by a stop or flange on the selector valve. Fig. D-2 shows the kick-down valve in the actuated position.
Saab 900
General, road testing and fault diagnosis
Operation in position D - 3rd gear Pressure control takes place in the same way as in position 2 (2nd gear), except that in the throttle valve position shown (minimum throttle opening) no throttle pressure or modulated throttle pressure acts on the two ends of the primary regulating valve. Shift control is provided by the 2nd-3rd shift valve moving against spring force under the influence of governor pressure (2). This permits system pressure (3) to reach the rear clutch (15) and the release side of the front servo via the flow restrictor. Since the release side of the servo has a larger area than the application side, the front servo will disengage the brake band. The rear clutch, which is now engaged, in conjunction with the front clutch, provides 3rd gear. The absence of throttle pressure, as mentioned above, will cause the 2nd-3rd shift valve to move earlier under the influence of governor pressure, thus providing an upshift to 3rd gear at low speed.
Operation in position 1 Pressure control of the front pump is provided in the same way as in position D or 2. The selector valve directs system pressure (5) to the front clutch, the governor and the 1st-2nd gear shift valve. In the position shown, the governor pressure (2) acting on the 1st- 2nd shift valve is to too low to overcome the spring pressure. The result is that the valve prevents system pressure (5) from reaching the application side of the front servo. System pressure (6) can reach the rear servo, however.
Saab 900
440-11
440-12
General, road testing and fault diagnosis
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Hydraulic circuit in positions N (."Jeutral) and P (Park) automatic transmission Nos. 008, 009, 011,013,014,015, 016, 017 1 Torque converter. 8 Primary regulating valve 15 16 2 Lubricating oil 9 Secondary regulating valve 17 System pressure 3 From oil pump 10 2nd-3rd shift valve 18 Torque converter pressure 4 To front clutch 11 1st-2nd shift valve 19 5 Rear clutch 20 6 Front servo 12 Regulating valve 21 7 Rear servo 13 Governor 14 Selector valve
SubSOO
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to sU~':'ln
General, road testing and fault diagnosis
440-13
1111S1-21
R
S 4/647
Hydraulic circuit in position R (Reverse) automatic transmission Nos. 008, 009, 011, 013, 014, 015, 016, 017 1 Torque converter 8 Primary regulating valve 15 2 Lubricating oil 9 Secondary regulating 16 valve 17 3 From oil pump System pressure 4 To front clutch 10 2nd-3rd shift valve 18 Torque converter pressure 11 1st-2nd shift valve 19 5 Rear clutch Throttle pressure 12 Regulating valve 20 6 Front servo 13 Governor 21 7 Rear servo 14 Selector valve
Saab 900
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to suction side
440-14
General, road testing and fault diagnosis
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Hydraulic circuit in position D (1st gear) automatic transmission Nos. 008, 009, 011,013,014,015,016,017 1 Torque converter 8 Primary regulating valve 15 16 2 Lubricating oil 9 Secondary regulating System pressure 3 From oil pump valve 17 4 To front clutch 10 2nd-3rd shift valve 18 Torque converter pressure 11 1st-2nd shift valve 19 5 Rear clutch Throttle pressure 12 Regulating valve 20 6 Front servo Governor pressure Shift valve piston pressure 7 Rear servo 13 Governor 21 14 Selector valve
Saab 900
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to suction si,
General, road testing and fault diagnosis
440-15
0-2
S 4/649
Hydraulic circuit in position 0 (2nd gear) automatic transmission Nos. 008, 009, 011, 013, 014, 015, 016, 017 1 Torque converter 8 Primary regulating valve 15 16 2 Lubricating oil 9 Secondary regulating System pressure valve 17 3 From oil pump Torque converter pressure 10 2nd-3rd shift valve 18 4 To front clutch Throttle pressure 11 1st-2nd shift valve 19 5 Rear clutch Governor pressure 12 Regulating valve 20 6 Front servo Shift valve piston pressure 13 Governor 21 7 Rear servo Kick-down pressure 14 Selector valve Modulator pressure
$aab 900
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to suction side
440-16
General, road testing and fault diagnosis
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D-3
S 4/650
Hydraulic circuit in position 0 3rd gear automatic transmission Nos. 008, 009, 011, 013, 014, 015, 016, 017 1 Torque converter 8 Primary regulating valve 15 16 2 Lubricating oil 9 Secondary regulating System pressure valve 17 3 From oil pump 10- 2nd-3rd shift valve 18 4 To front clutch Torque converter pressure 11 1st-2nd shift valve 19 5 Rear clutch Governor pressure 12 Regulating valve 20 6 Front servo 7 Rear servo 13 Governor 21 14 Selector valve
Saab 900
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to suction sidl
General, road testing and fault diagnosis
440-17
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Hydraulic circuit in position 1 (1st gear automatic transmission Nos. 008, 009, 0,', 013, 014, 015, 016, 017 1 Torque converter 8 Primary regulating valve 15 2 Lubricating oil 9 Secondary regulating 16 System pressure 3 From oil pump valve 17 4 To front clutch 10 2nd-3rd shift valve 18 Torque converter pressure 11 1 st-2nd shift valve 19 5 Rear clutch Throttle pressure 6 Front servo 12 Regulating valve 20 Governor pressure Modulator pressure 7 Rear servo 13 Governor 21 14 Selector valve
Saab 900
Kick-down valve Throttle valve Modulator valve Oil cooler Accumulator N-D Accumulator 1-2 Return to suction side
440-18
General, road testing and fault diagnosis
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~:e:G:.Hhe bush im:the pump:.housing, the stator mOIlJJilting plate;, the small pump. m~ar' and' the sear.
Oil pump, dismantled. Turbine shaft removed.
1 2 3 4
Pump Pump Pump Stator
housing plate gears mounting plate
Assembly Before, assembly, lubricate all parts with automatic transmission fluid. Assemble in reverse order. Use tool 87 90 248 to align the pump. Note: The tool must move freely: after the bolts have been tightened.
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Check the O-ring on the outside of the nousing.
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Oil pump
1 Tool 87 90 248 for centring the pump 2 O-ring 3 Pump housing
The oil pump gears are without a chamfer on one side. The unchamfered side must face the separator plate.
Saab 900
"'''"-.-'':.'
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Dismantling, assembty
472-31
Replacement of sealing ring with "he pump removed Remove the seal, see Fig.
I Use tool 87 90 941 to fit the seal. Use the side of the tool which enables the seal to be pressed 2.5 mm elow the edge of the pump housing. ...:.
Care must be taken when fitting the oil pump to the torque converter.
Identification number
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Saab 900
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472-32
Dismantling, assembly
Assembly of torque converter and oil pump 1 Turn the transmission face up and place the torque converter in position. 2 Fit locating studs, tool number 87 90 438, in the threaded holes for securing the oil pump. Make sure that the holes for the pump drive coincide with the drive pins on the torque converter. Lubricate the O-ring on the pump and push it into place. Then remove the locating studs and tighten the pump. 3 Fit the transit support to the torque converter. Turn the transmission upside down.
Replacing the turbine shaft ball bearing 1 Remove the circlip 2 Carefully tap the end of the turbine shaft with a plastic mallet until the shaft and bearing are free. 3 Remove the bearing. 4 Assemble in reverse order.
$aab 900
Dismantling, assembly
472-33
Dismantling the front clutch
I 7 8 9 10 11 12 13
1 2 3 4 5
Circlip, 1.15-1.20 mm Input shaft Thrust washer Hub A. Outer clutch plates B. Inner clutch plates 6 Pressure plate
1 Remove the input shaft circlip. Collect the thrust washer. 2 Lift out the front clutch hub. 3 Remove the clutch plates and pressure plate. 4 Remove the circlip and return spring or springs.
5 Use compressed air to remove the piston. 6 Check the piston sealing ring, the O-ring and the clutch plates for damage and wear. Replace any damaged parts. Check the splines on the front clutch cylinder (towards the rear clutch) and the sealing surface against the sun wheel shaft.
Saab 900
Circlip, 1.15-1.20 mm Return spring (2 springs) Piston sealing ring Piston O-ring Front clutch cylinder Steel ring
472-34
Dismantling, assembly
Assembly 1 Lubricate all parts before assembly. In addition, soak the inner clutch plates in automatic transmission fluid before assembly. , . l' ,j
2 Fit the piston, using tool 8790 107. 3 Check that the steel ring is correctly mounted in position on the piston.
4 Fit the return spring (or return springs) with the convex side facing down, towards the piston. Fit the circlip (1.15- 1.20 mm). 5 Fit the pressure plate with the flat side facing up. Check that the outer clutch plates are flat. If they are not, replace them. 6 When fitting the set of clutch plates, use the thin steel plates and then apply a load to the clutch plate assembly using tool 87 91 048 (weighing 2.27 kg).
7 Make sure that the clearance between the outer friction plates and the input shaft flange in the drum is 0.10-0.40 mm, measured from the upper friction plate to the shoulder on one of the teeth in the drum. If the clearance is greater than 0.40 mm, replace one of the thin steel plates by a thick plate, and continue until the clearance is between 0.10 and 0.40 mm.
Saab 900
Dismantling, assembly
472-35
2 1
I 1 Outer.friction plate 2 Flange for input shaft 3 Input shaft
8 Fit the hub and the thrust washer in place. 9 Check that the bush on the input shaft is in good condition. At the same time, check that the seals on the shaft rotate freely in their grooves. If the rings have jammed, check that the torque converter housing has not been damaged. 10 Insert the input shaft into the clutch cylinder and fit the circlip (1.15-1.20 mm). 11 When the set of clutch plates and the input shaft have been fitted into the front cylinder, check that the input shaft can be turned by hand when the front sun wheel shaft has been pushed into the hub and is held stationary.
Saab 900
472-36
Dismantling, assembly
Clutch plates The clutches are fitted with steel plates and friction plates. The steel plates (outer plates) have serrations round the periphery which engage in the clutch cylinder. These plates may be flat, dished or deeply dished, depending on the demands of the clutch. Flat plates are always fitted in the front clutch and dished plates are always fitted in the rear.clutch. The plates can be identified by the number of gaps in the peripheral serrations (see Fig.).
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The friction plates (inner plates) are always flat and have internal serrations which engage in the clutch hub. The plates are lined with friction material.
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Check that the friction linings are not cracked or heavily charred. If they are, replace them. If the linings have a uniform dark colour they may be refitted.
1 Outer plate without gaps in the serrations. Deeply dished plate. 2 Outer plate with four gaps in the serrations. Slightly dished plate. 3 Outer plate with two gaps in the serrations. Flat plate. 4 Spacer washer, can be replaced by a slightly dished outer plate and a friction plate (furbo). 5 Inner plate for the rear clutch. Grooved friction lining. Inner plate for the front clutch. Smooth friction lining. 6 Outer plate with three gaps in the serrations. Flat, thick plate.
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Saab 900
Dismantling, assembly
472-37
Rear clutch (Turbo 5 plates, others 4) To dismantle
I ·9 10 8b Components of the rear clutch 1 2 3 4 5 6
7 Circlip 8 A. Outer clutch plates B. Inner clutch plates 9 Circlip 10 Pressure plate 11 Spacer washer (not Turbo) Outer and inner clutch plates, Turbo
Rear clutch cylinder O-ring Piston Piston sealing ring Spring Washer
1 Remove the circlip, pressure plate and clutch plates.
2 Compress
the return spring, using tool 87 90 081 in a press and remove the circlip, washer and spring.
Note: The end face of the sun wheel is a bearing surface. Take care not to damage it.
3 Use compressed air to remove the piston. Inspect the parts for damage and wear and replace any that are worn or damaged. Lubricate all parts before assembling them. In addition, soak the inner plates in automatic transmission fluid before fitting them. Check the outside of the cylinder for scratches or charring. Check the bush in the end of the sun wheel, the surface of the thrust bearing and the teeth.
Saab 900
F; ,
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472-38
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Dismantling, assembly
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To assemble
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1 fit the piston, flat side down, using sleeves 87 90 081 and 87 90 693. Lubricate liberally with Vaseline.
2 Place the. Ilettlrn' spring on the piston. 3 Place the spring seat on the spring. 4 Compress the spring in a press, using tool 8790 081, and fit the circlijJ.
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5 Place the rear clutch in the cylinder (transmission assembled up to and including the centre support). Stand the transmission in a vertical position. Place sleeve 83 90 114 in the clutch. Mount the stand with dial indicator as shown in the Fig. Blow compressed air into the hole for the supply to the rear dutch and take a reading (stroke of the rear; clutch piston), which should be 1.5-2.0 mm. Circlips No. 8706491 = 1.15-1.20 mm No. 93 49 002 = 1.70-1.75 mm No. 87 06 368 = 0.95-1.00 mm
6 Note that the outer plates are dished and that the dishing must be in the same direction. Two clutch plates are deeply dished. Start assembly of the clutch plates with a slightly dished outer clutch pl,ate.
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Saab 900
Dismantling, assembly
472-39
Turn the convex side of the plate towards the piston, see Fig. Fit the pressure plate last. 7 Fit the circlip.
2 Rear clutch, jTurbo
i I
·2 Rear-clutch, not Turbo
1 Dished clutch plates 2 Deeply dished clutch plates 3 Spacer washer
Clutch plates The clutch plates are fitted with steel plates and fric.Ion plates. The steel plates (outer plates) have serrations round the periphery which engage in the clutch cylinder. These plates may be flat, dished or deeply dished, depending on the demands of the clutch. Flat plates are always fitted in the front clutch and dished plates are always fitted in the rear clutch. The plates can be identified by the number of gaps in the peripheral serrations (see Fig.). The friction plates (inner plates) are always flat and have internal serrations which engage in the clutch hub. The plates are lined with friction material. Check that the friction linings are not cracked or heavily charred. If they are, replace them. If the linings have a uniform dark colour they may be refitted.
1 Outer plate without gaps in the serrations. Deeply dished plate. 2 Outer plate with four gaps in the serrations. Slightly dished plate. 3 Outer plate with two gaps in the serrations. ;Phis, flat plate. 4 Spacer washer, can be replaced by a slightly dished outer plate and a friction plate (Turbo). 5 Inner plate for the rear clutch. Grooved friction lining. Inner plate for the front clutch. Smooth friction lining.
Saab 900
I
472-40
Dismantling, assembly
Planet gear To dismantle 1 Withdraw the centre support from the planet gear and remove the one-way clutch. 2 Use a screwdriver to remove the circlip from the planet carrier and with draw the one-way clutch holder. • ,...
~.....
....~
...
~
S2fiG6
Planet gear with centre suppott and one-way clutch mechanism
1 2 3 4 5 6
To assemble 1 Insert the one-way clutch holder and secure it with the circlip. 2 Fit the one-way clutch. Note: the flange on the inner roller cage should face outwards. 3 Place the centre support in the planet carrier and check that it is free to turn clockwise.
I
!, II
Check the contact surface of the one-way clutch on the centre support (slight wear is permissible). Check the bush in the one-way clutch holder, the teeth of the gears and the thrust washers. Check the outer side in contact with the rear brake band (scratched or charred).
Saab 900
Centre support One-way clutch Circlip One-way clutch holder Thrust washer Planet gear
Dismantling, assembly
472-41
Ring gear, output shaft and governor mounting To dismantle and assemble 1 Remove the socket cap screw using a 4 mm Allen key and remove the governor mounting.
I 2 Remove the circlip and withdraw the shaft. Assemble in reverse order. Note: Check that the seals move freely in )he grooves.
Saab 900
472-42
Dismantling, assembly
1-~
1 2 3 4 5
Lock washer for governor weight Screws Governor weight Governor housing Governor valve
6 Spring 7 Spindle 8 Governor mounting 9 Cover plate
To dismantle 1 Remove the governor from its mounting. 2 Remove the screws for the cover plate on the governor housing. 3 Remove the lock washer and withdraw the governor weight and valve.
To assemble Lubricate all components with automatic transmission fluid before assembly. Assemble in reverse order. Check that the governor valve moves freely. Le. that the valve moves when the governor is turned upside down. If the valve binds, dismantle it and wash the components meticulously. Use a fine whetstone to smooth out any scratches on the valve. Note: Be careful not to round the edges of the valve with the whetstone.
Saab 900
Dismantling, assembly
472-43
Pinion shaft To dismantle When dismantling the pinion bearing, follow the procedure described for dismantling the transmission up to the point where the pinion with bearing housing have been removed. Continue dismantling as follows: 1 Remove the two bolts holding the seal housing over the pinion nut. 2 Use socket 8791 113 to remove the pinion nut. Use fixture 87 90 636 mounted in a vice and retainer ring 87 90 651. Fit two M8 screws in the fixture as a stop for the pinion bearing housing. Use retainer ring 87 91 097 for the 9:33 final drive. 3 Withdraw the pinion from the bearing housing. 4 Press the rear pinion bearing off the pinion. Use the fixture and the retainer ring (see point 2) for support. Press the bearing off little by little, releasing the pressure each time and turning the pinion clockwise so that its teeth are not damaged by the retainer ring. Check the bearing and bearing race for damage. Inspect the sealing surface for the shaft seal on the pinion, and check the pinion teeth for wear or surface damage.
5 Remove the rear bearing race using tool 87 91 378 together with 83 90 189.
Saab 900
I
If "
472-44
I! L
~lP~
Dismantling, assembly
r~' 1
,
6 Remove the shaft seals in the same way as the rear bearing race. 7 Press out the front bearing race, using tool
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7841 141. /
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1 Pinion 2 Rear bearing 3 Rear bearing race 4 Sealing rings 5 Bearing housing 6 O-rings 7 Spacer 8 Front bearing 9 Front bearing race 10 Nut 11 Seal housing
To assemble 1 Clean the ventilation channel in the bearing housing with compressed air,
Saab 900
Dismantling, assembly
472-45
2 Press the front bearing race home against the stop in the bearing housing. Use tools 87 90 461 and 87 90 189.
I 3 Fit the pinion seals as follows, using tools 87 90 636 and 87 90 025 for support and as guides: Position the bearing housing and tool 8790 900, which has a locating stud and spacer stop for fitting the inner and outer seals. Press the inner seal against the stop, using side A of the tool. Then turn the tool and press the outer seal against the stop, using side B.
8
Saab 900
A
472-46
Dismantling, assembly
Fit the seals as shown in the Fig. Note the distance between the seals. Lubricate the lips ofthe seals with Vaseline.
• • S 7723
4 Fit the rear bearing race in the bearing housing.
5 Fit the rear bearing on the pInion. Use tool 87 90 636 and tool 87 90 982 for support.
87906 36
Saab 900
Dismantling, assembly
472-47
6 Fit the pinion in the bearing housing. Use tool 87 91 006 on the pinion to avoid damaging the seals when the pinion enters the housing.
I Then remove the tool. Place the spacer and front bearing in position, oil the threads and screw on the nut. 7 Mount the pinion bearing housing in tools 8790 636 and 8790651. Oil the bearings and tighten the nut with the specified torque, using socket 8791 113.
Tightening torque: 215-264 Nm (155-195Ibfft)
8 Use the torque wrench to check the bearing preload. Check the pre-loading torque while the pinion is rotating at 10-100 rpm. Pre-loading torque, new bearings: 2.2-2.7 Nm (1.6-2.0 Ibf tt). Old bearings (used more than 2000 km): 0.9-1.5 Nm (0.66-1.1 Ibftt).
9 The torque can be adjusted by fitting a spacer of different thickness.
Saab 900
l~
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"
~i·
472-48
Dismantling, assembly
Shims for pinion bearing adjustment
F:
«,f
" l·
ii"
9341 9341 9341 9341 9341 9341 9341 9341 9341 9341 9341 9341 9341
009 017 025 033 041 058 066 074 082 090 108 116 124
2.850 2,925 3.000 3.075 3.150 3.225 3.300 3.375 3.450 3.525 3,600 3.675 3.750
± ± ± ± ± ± ± ± ± ± ± ± ±
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
2.825-2.875 2.900-2.950 2.975-3.025 3.050-3.100 3.125-3.175 3.200-3.250 3.275-3.325 3.350-3.400 3.425-3.475 3.500-3.550 3.575-3.625 3.650-3.700 3.725-3.775
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Servo pistons
) Free length
Springs
mm
mm
Wire diameter
Outside diameter
Number of turns
inch
mm
inch
mm
0.103
2.64
Front servo piston
1.32
33.6
4.8
0.885
22.50
Damper piston
0.50
12.64
2.83
0.036
0.91
0.492
12.5
Rear servo piston
1.95
49.6
5.1
0.116
2.95
1.06
27.0
N-D accumulator
3.08
78.3
16.0
0.092
2.34
0.709
18.0
1-2 accumulator .
2.67
68.0
19.5
0.078
2.0
0.521
13.25
3rd-2nd drain valve
0.70
17.8
11.0
0.022
0.56
0.287
7.25
Front servo There are three versions of the front servo pistons, with holes of different sizes for the push rod. 008,013,015,0170.85-0.95 mm0 (marked "3711") 0099 0.45-0.55 mm0 (marked "370T') 011,014,016 0.50-0.60 mm0 (marked "3710")
)
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Front servo piston, disman-
tled 1 2 3 4 5 6
Saab 900
7 Stop ring Servo piston 8 Circlip 9 Spring seat a-ring 10 Spring for servo piston a-ring 11 a-ring a-ring 12 Cover Damper piston Spring for damper piston
)
Dismantling, assembly
472-49
Rear servo Rear servo piston for type 008, 009, 011, 013 and 014 transmissions (exchangeable for new version).
I
Rear servo piston, dismantled
The new version of the rear servo piston is for type 015,016 and 017 transmissions. Can be fitted as a replacement for servo pistons of earlier type.
Rear servo piston, new version
Use tool 87 91 345 for removing and fitting the rear servo spring.
Saab 900
472-50
Dismantling, assembly
Valve body
~~113:
L11 110
1 2 3 4 5 6 7 8 9
10 11 12 13 14 15
Primary regulating valve Secondary regulating valve Carrier and cam for kick-down valve Kick-down and throttle valve Lower part of valve body Regulating valve Modulator valve Selector valve 1st-2nd shift valve
)
2nd-3rd shift valve Upper part of valve body Dividing plate Selector valve catch Oil pipe plate Ball valve
) To dismantle Note: All work on the valve body should be carried out in a room with an extremely high standard of cleanliness. 1 Remove the two bolts for the cam and the catch. 2 Withdrawn the selector valve, the kick-down valve, the throttle valve and the springs. 3 Separate the upper and lower parts of the valve body by removing the six bolts from the top of the body and the three bolts from the bottom. Remove the modulator valve. 4 Remove the eight screws retaining the oil pipe plate.
Saab 900
Dismantling, assembly
472-51
5 Lift off the dividing plate. Remove the ball valves, the spring and the stop for the throttle valve spring. 6 Remove the stop for the flow restrictor and remove the restrictor. 7 Remove the valves and the spring.
8 Remove the three bolts from the end plate and remove the· primary and secondary regulating valves.
I
9 Remove the bolts from the covers on the upper valve body and dismantle the 1st-2nd and 2nd3rd shift valves.
Note: Before assembly, make sure that all parts are scrupulously clean and free from scratches. If the valves are scratched, smooth them down carefully using a fine whetstone. N.B. Do not round off the edges with the whetstone. Check that the valves move freely in their cylinders.
To assemble 1 Before assembly, dip the valves in automatic transmission fluid. 2 Fit the secondary regulating valve and spring. 3 Fit the primary regulating valve and springs. 4 Fit the modulator valve and spring.
5 Fit the regulating valve (flow restrictor) and the stop.
6 Fit the throttle valve with spring and stop, and the kick- down valve with spring. 7 Place the spring and ball valve in the valve body as shown in the Fig. and place the dividing plate in position. 8 Fit the 1st-2nd and 2nd-3rd shift valves.
9 Screw the upper and lower parts of the valve body together and fit the oil pipe plate.
Ball valves
10 Fit the modulator valve. Tightening torque: 2-3 Nm (1.45-2.2 Ibf tt). 11 Fit the selector valve. 12 Fit the catch for the selector valve and the cam for the kick-down valve. 13
Check the position of the selector valve as described in point 24 on page 472-20.
14
Check the position of the kick-down valve cam as described in point 24 on page 472-21.
Saab 900
472-52
Dismantling, assembly
IIt !
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Transmission in car
:.'
Removing and refitting the centrifugal governor 1 Move the selector lever to position N. 2 Drain the automatic transmission. 3- Remove the support member or protective plate. 4 Clean the bottom part of the transmission round the rear oil pan. 5 Remove the bolts retaining the rear oil pan so that any remaining automatic transmission fluid can run out.
..
,
6 Rotate the oil pan a quarter-turn and remove it towards the rear over the cross-member. 7 Remove the centrifugal governor. If the governor is not accessible for removal, its position can be altered by rotating one of the front road wheels while holding the other one stationary.
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To dismantle and assemble the centrifugal governor, see page 42in this section.
,
To refit the centrifugal governor 1 Fit the governor so that the cover plate faces the pinion bearing housing. 2 Fit the rear cover. Make sure that it is thoroughly clean, that the gasket is undamaged and that no dirt will fall onto the cover when it is being inserted over the cross-member. 3 Fit the drain plug and the supporting member of protective plate. Lower the car to the floor. 4 Fill the transmission with fluid conforming to the specification in section 024. See section 440 "Checking the oil level".
Saab 900
/
Dismantling, assembly
472-53
Adjustment of front brake band The front brake band is not self-adjusting but is accessible for adjustment once the rear cover has been removed, see Fig. In other respects, follow the same procedure as described on page 27 in this section.
I
Saab 900
472-5 4
Dism antlin g, asse mbly
Removing and refitting the valve bod y To remove 1 Raise the car. 2 Remove the suppor ting member or protective plate under the power unit and clean the lower part of the transmission round the front cover. 3 Drain the automa tic transmission fluid .. 4 Undo the bolts retaining the front cover. 5 Remove the overflo w pipes, the suction strainer, the magnet, and pipes 13 and 14. Use tool 87 91 360.
6 Disconnect pipe NO.9 in the valve body and remove the holder for pipe No. 12. Then remove pipes 5, 6, 7, 8, 9, 10, 11 and 12. Use tool 87 91 360.
7 Disconnect the throttle cable.
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Saab 900
Dismantling, assembly
472-55
8 Remove the two bolts retaining the valve body and lower the valve body (the N-D accumulator together with the spring will drop down at the same time). Collect the delivery and lubrication oil pipes between the valve body and oil pump. The oil pump suction pipe is clamped to the oil pump and can be removed only after the bonnet, front panel, radiator, primary drive cover, sprockets and chain have been removed. For particulars of dismantling and assembling the valve body, see page 50in this section.
Note: If the 3rd-2nd drain valve is removed, it must be refitted together with pipe No. 15 before the valve body is fitted.
Fit the delivery and lubrication oil pipes to the oil pump and clamp them in position. Fit the delivery pipe about 27 mm from the front edge of the primary drive housing.
Note: Check that the O-ring on the V-shaped suction pipe is undamaged.
Fit the valve body and N-D accumulator together with the spring. At the same time, check that the oil pipes enter the valve body correctly. Make sure that the N-D accumulator lever engages correctly and coax the suction pipe into place when fitting the valve body. Fit the bolts at points 1-5 and align the valve body. Tighten the valve body bolts at points 3 and 4. Then remove bolts 1, 2 and 5 for fitting at a later stage together with filter and overflow pipes.
Saab 900
I
472-56
Dismantling, assembly
Using a mirror fitted with a light, check that the pipes are correctly positioned in the valve body.
Fit the throttle cable, making sure that it runs in the groove of the guide pulley. Check that the oil strainer seal is undamaged. Fit the sealing ring with its heavier part towards the suction pipe. Fit oil pipes 5-15, the overflow pipes and the oil strainer as shown in the diagram, see page 23in this section. Fit the front oil pan. Make sure that the pan is clean and fit a new gasket. Place the magnet in the oil pan. Tighten the pan with a torque of 11 Nm (8 Ibf tt). Fit the drain plug. Refit the support member or protective plate. Lower the car to the floor.
Note: Under no circumstances should fluid of type A. SUFFIX A or DEXRON be used. S 4/151
I:
j
2 Fill up with ATF fluid of Ford M2C.33G (or F) type. 3 Check and adjust the selector positions, see page 1 in section 444. 4 Check the oil pressure, see section 444. 5 Test the car on the road and fill in the test report form.
Saab 900
Location of the magnet in the oil pan.
472-57
Dismantling, assembly Parking pawl, checking and adjusting In connection with refitting the valve body, the clearance between the parking pawl and the ring gear may be changed. This could give rise to noise when the transmission is in position R. The clearance between the pawl and the ring gear can be checked through the rear cover. Replacement of the gear selector rod is not possible without removing the transmission from the car.
I
Move the selector rod to position R and measure the distance between the pawl and the crown of the tooth opposite it. This distance should not be less than 0.90 mm (0.035").
1
The selector rods are identified as follows:
Gear selector rod Length
Marking
Spare part No.
Short
3 rings
9344136
2 lugs
7542962
4 rings
9344144
4 lugs
7542970
5 rings
9344151
t Long
6 lugs
f I
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7542988
i I
3
_,II
..-,
I i
i~ 1 Ring gear
2 Pawl 3 Expanding pin 4 Plunger 5 Gear selector rod
Saab 900
5
1-------...,...::;....
472-58
Dismantling, assembly
2 If the pawl clearance is outside the specified limits by only a small amount, this can be remedied by a combined adjustment of the 1st-2nd accumulator plate and the valve body. Such adjustment affects the lever so that the gear selector rod is moved lengthwise.
4
=+--
==
1
1 2 3 4
N-D accumulator lever Accumulator plate Lever Gear selector rod
3 Check the operation of the pawl as follows:
1
Allow the pawl to rest against a tooth crown in position P. Rotate the ring gear so that the pawl enters the gap between two teeth. A suitable pawl should be chosen for mounting of the lever and the accumulator plate. Press the gear selector rod rearwards so that the pawl bottoms in the gap between two teeth on the ring gear, without the expanding pin leaving the plunger. If half the expanding pin is visible outside the pawl, the pawl is of the correct length, but if the whole of the expanding pin is visible a longer pawl should be used. If no part of the expanding pin is visible, use a shorter pawl.
-t I
4
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:
3
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5
-=.f~ ;1'I:11-,-----~~ I
I
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1 2 3 4 5
Length
Marking
Spare part No.
Short
Violet
7542384
!
Red
7542376
Blue
7542368
White
7542350
Green
7542343
Long
Ring gear Pawl Expanding pin Plunger Gear selector rod
--.)
Saab 900
Differential and pinion/crown wheel gear
473-1
Differential and pinion/crown wheel gear Adjusting the position of the pinion gear. 473-1 Before measuring . . . . 473-4 Measuring - shimming . . . . . . . • . . . 473-5
Differential 473-9 Inner driver with differential bearing seats . . . . . . . . . . . . . . . 473-10
The crown wheel and pinion are a matched pair, so both must be replaced together. The parts are tested together for noise and the optimum setting for minimum noise output is measured. The key measurements in regard to the pinion and crown wheel are firstly the distance from the end face of the pinion to the centre of the crown wheel and secondly the backlash between the teeth. These measurements and the mating number are stamped into both parts at the time of noise testing. When the pinion and crown wheel are installed, these measurements must be accurately adjusted by means of shims and a special measuring instrument. The pinion gear shims are placed next to the bearing housing of the pinion shaft bearings and the crown wheel (differential) shims are distributed between the two differential bearing seats.
I
Adjusting the position of the pinion gear The particulars for adjusting the distance from the pinion gear to the centre of the crown wheel are stamped into the end face of the pinion, see example below.
End face of pinion
\ ote: Before dismantling the transmission, always measure the positions of the pinion and crown wheel. Tllis provides a check on whether the setting may have been incorrect. If the pinion shaft and crown wheel assembly has been in use for less than 10,000 km, the setting can be adjusted. After longer mileages, when the gears will have worn themselves into a certain position, the parts should be reassembled with the same settings as were measured prior to dismantling.
+3 = measurement for pinion setting. R913 = mating number, also stamped on crown wheel. = pinion not offset - shaft centreline intersects crown wheel centreline. All pinions are marked 0 and this datum has no relevance to the adjustment.
o
Saab 900
473-2
Differential and pinion/crown wheel gear
Before measuring
\
The following preparations must be made prior to measuring the pinion gear settings:
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The pinion shaft nut must be tightened to: (Type 37) 215-264 Nm (158-195 Ibf ft). The torque required to rotate the pinion in the housing should be 2.2-2.7 Nm (1.2-2.0 Ibf ft). This applies to new, lightly oiled bearings. For old bearings that have been in use for more than 2,000 km. the torque should be 0.9-1.5 Nm (0.65-1.1 Ibf ft). When checking the bearing pre-load using a dynamometer (attached to a cord wound round the pinion bearing housing) the following values should be obtained: New bearings: 34-58N (7.8-13.4 Ibf) Old bearings: 19-30 N (4.4-6.9 Ibf) Tool 83 90 155 consists of a measuring jig with attached indicator dial. A ground gauge block is provided for calibration of the dial and is to be laid against the calibration stops of the instrument. The distance between these stops and the centreline of the tool is always exactly 60.000 mm, see Fig. Measure the pinion gear position as shown in the Fig.
)
1 Crown wheel 2 Pinion 3 Standard measurement
Measuring 1 Check that the pointers of the instrument are zeroed when the measuring point touches the gauge block, see Fig.
)
Saab 900
Differential and pinion/crown wheel gear
473-3
2 Place the instrument in the differential housing with the point applied to the flat end of the pinion gear and take a reading.
I ,.
3 When the pinion gear is correctly positioned, the dial should show the number of hundredths of a millimetre (+ or -) stamped into the pinion, with a permissible tolerance of ± 0.05 mm.
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If the pinion is marked -7 the dial should give a reading of
-0.07 ± 0.05 mm.
Check the dial to make sure whether the reading is positive or negative.
I
If the pinion is marked + 3, the dial should give a reading of +0.003 ± 0.05 mm.
Saab 900
473-4
Differential and pinion/crown wheel gear
Shimming If the measured reading is outside the permissible tolerance, adjustment will be necessary. This should be done with shims placed between the pinion bearing housing and the transmission case, see Fig.
1 Pinion bearing housing 2 Transmission case 3 Shims (see table)
Shim table Shims
Location
Thickness, mm Between pinion 0.10 bearing hous0.15 ing and trans0.30 mission case
Part No. 9334962 9334970 9334988
Checking the measuring jig The measuring jig is a precision-built tool and should be handled with care to avoid knocks and deformation. If there is reason to suspect that the jig may have been damaged in such a way as to give incorrect readings, it can be measured as a check. The dimension indicated in the Fig. should be measured for this purpose.
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Saab 900 I
Differential and pinjon/crown wheel gear
473-5
Adjusting the crown wheel backlash / Certain particulars for adjustment of orown wheel backlash are stamped into the crown wheel as shown in the Fig. The backlash should be checked at four points round the circumference of the crown wheel and must deviate by more than 0.05 mm from the specified measurement of 0.17 mm. Crown wheel backlash is adjusted by means of shims. Up to four shims may be used in suitable combinations.
Crown wheel markings 870488 = 9.35 = 73-04 = = 02 -17 =
Component number (not part No.). ratio. date of manufacture (for identiiication). MatedaLcode. Backlash 0.17 mm .± 0.05 mm. (Note: if this information is not specified, 0.17 ± 0.05 r mm should·be assumed.) = Mating number, also stamped on the pinion. 0
1330
Measuring and shimming Adjustment of differential bearings Note: Any adjustment must be made before the pinion shaft is refitted. (If only the final drive has been dismantled for replacement of the differential bearings, the crown wheel must also be dismantled before the bearing pre-load can be adjusted.
Saab 900
I
473-6
Differential and pinion/crown wheel gear
1 Place the differential in the transmission case. 2 Fit the left-hand bearing seat (the one with the speedometer drive) without shims and tighten the bolts with the specified torque. Tightening torque, left-hand bearing seat: 20-25 Nm (15-18.5 Ibf ft) 3 Oil the differential bearings and fit the right-hand bearing seat. Tightening torque, right-hand bearing seat: 2.2 Nm (1.65 Ibf ft)
4 Use a feeler gauge to measure the clearance between the transmission case and the bearing seat at two points opposite each other and take the average of the two measurements. Then select shims corresponding to this result plus an increment of 0.20 mm to obtain the correct bearing pre- loading.
Note: The method described above applies to both new and old bearings. The pre-load obtained in this way can be measured by means of a torque wrench and driver 8790818.
Saab 900
Differential and pinion/crown wheel gear
473-7
Ensure that adjustment is carried out to the correct values. The following values are for the rolling torque. New, lightly 1.8-2.8 Nm Bearings used for 0.8-1.3 Nm
oiled bearings (1.3-2.0 Ibf ft) more than 2,000 km (0.6-1.0 Ibf ft)
Alternatively, the old shim combination can be refitted, followed by adjustment to the correct rolling torque and backlash. Shims of four different thicknesses can be used in suitable combinations. The available thicknesses are shown in the table.
Shim table Shims
Location
)
Thickness, mm
Part No.
0.10 0.15 0.30 0.50
8341 8341 8341 83 41
-------'--------:.....:....~---'----~-
Between differential bearing seat and transmission case
604 612 620 638
Note:
The resulting set of shims should then be distributed between the right-hand and left-hand sides to give the correct gear backlash.
Saab 900
I
473-8
Differential and pinion/crown wheel gear
Adjusting the crown wheel backlash 1 Place the differential complete with crown wheel in the transmission case. .'
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2 Fit the left-hand bearing seat (the one with the speedometer drive) without shims and the righthand bearing seat with the selected set of shims. Tighten the bolts with the specified torque. Tightening torque,left-hand and right-hand bearing seats: 20- 25 Nm (15-18.5 Ibf ft) 3 Mount the indicator dial as shown in the Fig. and measure the backlash. Measure the backlash at three points, 0.8-0.23 mm.
4 Calculate the difference between the measured backlash and the desired backlash. Then move shims of suitable thickness over to the left-hand bearing seat. Afterwards, measure the backlash again as an extra check.
Note: The preselected set of shims must be used for adjusting the backlash. The total thickness of the set must not be altered.
Saab 900
)
Differential and pinion/crown wheel gear
473-9
Differential Removal, dismantling 1 Remove the final drive cover.
2 Remove both differential bearing seats together with inner drivers. Collect the shims and remove the differential. 3 Remove the speedometer drive and press both journal bearings out of the differential housing, using tools 8996084, 8790768 and 8995 177. For replacement of the outer bearing races, see "Dismantling the inner driver", page 475-2. 4 Remove the locking pin which secures the dif-
ferential pinion shaft and carefully tap out the shaft. Collect the pinions and wear washers. 5 Undo the crown wheel bolts and remove the crown wheel.
Assembly, fitting 1 Replace worn or damaged parts.
2 Press the journal bearings into the differential housing and fit the speedometer drive. Use tool 8790487.
3 Fit the differential and differential bearing seats in the transmission case. Check the bearing preload and adjust the set of shims, if necessary (see inner driver and bearing seats). 4 Remove the differential and bearing seats
5 Fit the crown wheel and tighten the bolts with the specified torque. Secure the bolts with locking fluid. Tightening torque: 90 ± 10 Nm (66 ± 7 Ibf ft)
Saab 900
I
473-10
Differential and pinion/crown wheel gear
6 Place the pinions and wear washers in their positions and press in the differential pinion shaft. Fit the locking pin. ~.
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7 Fit the differential and differential bearing seats in the transmission case. 8 Check and if necessary adjust the crown wheel backlash (see "Inner driver with bearing seats").
9 On final assembly of the differential bearing seats, coat the threads of the 12 bolts with sealing compound.
Tightening torque 23-28 Nm (17-21 Ibf ft)
10 Fit the final drive cover.
J
Inner driver with differential bearing seats To remove" Undo the differential bearing housing retaining bolts and remove the housing together with the inner driver using puller 87 90 776 and sliding hammer 83 90 270. Collect the shims.
To dismantle 1 Remove the circlip from the driver.
'C' (f)
Saab 900
~
Differential and pini,on/crownwheel gear,
473-11
2 Press the driver out of the differential bearing housing. 3 Using a screwdriver, remove the sealing ring without damaging the bearing bracket. 4 Remove the speedometer drive from Jhe lefthand bearing seat. 5 Press out the ball bearing, using tool 7841067.
I 6 Remove the differential bearing races, using a suitable drift. A washer is located inside the bearing race in the right-hand differential bearing seat (the one without the speedometer drive) and its purpose is to improve lubrication of the ball bearing. 7 Remove the O-ring from the groove in the bearing seat.
~ ~'1'
9 8765
4
I 1 _-.._!!4SJE
Inner driver with bearing
1 2 3 4 5 6 7 8 9
Saab 900
Inner driver Spring with plunger Sealing ring Bearing bracket Ball bearing Circlip Oil level washer Bearing race a-ring
473-12
Differential and pinion/crown wheel gear
To assemble 1 Press the ball bearing into the bearing bracket, using tool 7841 141. ,, .I
I·:
r 2 Guide the oil catcher washer into the groove in the seat of the right-hand bearing and press in the bearing race, using sleeve 83 90 114.
3 Using drift 87 90 800, press in the sealing rings until they are about 2 mm inside the face of the bearing seat.
4 Adjust the bearing pre-load and the backlash (right-hand side only), see page 473-6. 5 Press the bearing seats onto the driver shaft using sleeve 78 41 067. 6 Fit the circlip, using circlip pliers. 7 Fit the speedometer drive. 8 Fit the a-ring in the groove in the bearing seat.
Saab 900
III
Differential and pinion/crown wheel gear
473-13
To fit See page 473-6 for adjustment of the differential bearing pre-load and adjustment of the backlash. 1 Check that the a-ring is fitted on the bearing
seat. Insert the spring with plunger into the hole in the end of the driver shaft. 2 Place the selected combination of shims on the two bearing seats and mount the seats, complete with inner driver, on the transmission.
Coat the threads of the 12 bolts with sealing compound. 3 Check the backlash while tightening the bearing seat. Tighten the retaining bolts with the specified torque. Tightening torque, differential bearing seats 23-28 Nm (17-21 Ibf ft)
4 Check the backlash by measuring it at four points.
Saab 900
I
Universal joints
475-1
Universal joints Inner universal joint To remove . . . . .
• 475-1 . . • . • 475-2
. 475-2 . 475-4
To fit . . . . Inner drive shaft
Inner universal joint The inner universal joint consists of a driver running in ball bearings in the differential bearing seat and splined onto the differential gears. The driver is locked axially by means of a circlip inside the ball bearing and also by a spring and a plunger at the end of the driver which bears against the differential shaft.
I
The driver is removed from the transmission complete with the differential bearing seat. The external design of the driver is in the form of a sleeve in which there are recesses for the three-bearing universal joint of the inner drive shaft. When the car is in motion, the universal joint, which is fitted with needle bearings, can slide axially inside the driver sleeve at the same time as it is articulated. The universal joint is packed with grease and protected by a rubber gaiter. Lubrication of the joint is only necessary in connection with reconditioning or when it is removed for some other reason. Inner universal joint (and inner drive shaft)
S 4/152
Driver and tripod Saab 900
475-2
Universal joints
To remove l' a Undo the upper damper mOtlnfmg before rais-
ing the: car from the floor. Jack up the front assembly and remove the wheeL e the brake caliper and suspend it at the Remov 2 wheel housing, taking care not to damage the brake hose, and. thEHemove the brake disc. 3 Remove the large clip from the rubber gaiter on the inner universal joint When separating the inner universal joint, fit
o
cover 73 23 736 in the rubber gaiter to prevent the needle bearings from falling out and also to prevent dirt from entering the joint. Fit protective cover 78 38 469 on the inner driver. 4 Disconnect the track rod from the track arm, ustool ing upper the from nut the 89 95 409 and remove ball joint. Remove the bolts from the lower wishbone bracket. 5 Withdraw the drive shaft through the wheel housing and remove the entire front axle assembly. For particulars of removing the inner driver from the transmission and refitting it, see section 473; 6 If the rubber gaiter on the inner or outer universal joint is to be replaced, remove the shaft from the outer joint. See "Outer universal joint" on page 4in this section. The rubber gaiters can then be removed from the shaft.
To fit First make sure that the inner driver is thoroughly clean and then pack it full of grease. To be sure of using the right quantity, the gaiter should also be packed with grease, 130 g in all, of which the inner driver holds about 80 g.
Lubric ant Soft EP grease having a lithium-lead base which can withstand wide variations in temperature and load. Consistency: ESSO Beacon EP2 type or the equivalent.
Saab 900
Universal joints
475-3
2 Fit the rubber gaiters on the intermediate drive shaft and mount the shaft and rubber gaiter on the outer universal joint. see "Outer drive shaft" on page 4in this sectiol'l. 3 Pack the needle bear.ings with grease and mount them on the drive shaft.' F:it cover 73 23 736 in the rubber gaiter to preve-ritthemeedle bearings from falling out and dirtfrom"er.Jtering. Then push the shaft with rubber gaiter through the wheel housing. 4 Remove the cover from the 'rubber gaiter and push the shaft with needle bearings into the inner driver. Then fit the rubber gaiter and clips. 5 Fit the steering swivel member and track arm. 6 Fit the brake disc and brake caliper. 7 Place a jack under the outer end of the lower spring arm. Jack up slightly and fit the damper 1 ". nuts. 8 Fit the wheel and lower the car to the floor.
Caution The brake pads must be returned to their positions close to the brake disc by repeatedly pumping the brake pedal. This is of vital importance to ensure proper functioning of the brakes.
Saab 900
I
475-4
Universal joints
Outer universal joint The outer universal joint transfers the power from the intermediate shaft to the outer drive shaft. The outer drive shaft terminates in a bell with a spherical track in which six balls transmit the driving power from a hub. The intermediate drive shaft is splined onto the hub and secured axially by means of a circlip accessible through a recess in the hub. The hub, balls and outer shaft are individually matched and are not interchangeable. Lubrication of the joint is only necessary in connection with reconditioning or when it is removed for some other reason.
1
S 6/0'
Removal and refitting See Group 7, section 774.
6 Outer universal joint 1 2 3 4 5 6
Saab 900
Locknut Washer Hub Outer drive shaft Bearing with seals Outer universal joint
)
•
Saab Automobile AS Trollhattan, Sweden
Pnnled 10 Sweden. Graphic Systems AB. Gbg 1992.19104
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