Mercedes 4wd

4ETS for Passenger Cars & 4ETS for W163 Starting MY1998

1 327 HO 06 4ETS (WJB,RP,GC) 02-27-04

Objectives At the end of this session, you should be able to: • Identify which 2004 models have the 4ETS option • List the advantages of 4ETS • List 4ETS mechanical components and describe their function • Explain basic operation of 4ETS • Describe transfer case maintenance procedures • Describe the unique features of the W163 transfer case • Explain the operation and function of the W163 system

These technical training materials are current as of the date noted on the materials, and may be revised or updated without notice. Always check for revised or updated information. To help avoid personal injury to you or others, and to avoid damage to the vehicle on which you are working, you must always ref er to the latest Mercedes -Benz Technical Publication and follow all pertinent instructions when testing, diagnosing or making repair. Illustrations and descriptions in this training reference are based on preliminary information and may not correspond to the final US version vehicles. Refer to the official introduction manual and WIS when available. Copyright Mercedes-Benz USA, LLC, 2004 WIS document numbers shown apply to WIS Version USA/CDN at date of writing. Reproduction by any means or by any information storage and retrieval system or translation in whole or part is not permitted without written authorization from Mercedes -Benz USA, LLC or it's successors. Published by Mercedes -Benz USA, LLC Printed in U. S.A.

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Contents MY2004 4ETS vehicles Purpose and advantages of 4ETS Driving with 4ETS Additional 4ETS components 4ETS Brake torque control range 4ETS block diagram MY2004 ETS Maintenance and service Model W163 Off-roading with the W163 W163 Transfer case and controls Transfer case control unit W163 block diagram W163 service notes

4 6 9 10 19 21 22 25 27 29 32 33 34 3

MY2004 4ETS Vehicles

All ML-class vehicles All G-class vehicles C-class sedans & wagons with V6 engine-NEW for 2004 E-class sedans and wagons with V6 and V8 engines-NEW for 2004 S-class sedans with V8 engine-NEW for 2004

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AWD, 4WD, 4ETS and 4ETS+ • • •

“AWD” and “4WD” are used interchangeably by some manufacturers “Permanent” and “full-time” are sometimes interchanged, too Here’s the way MB retail training literature puts it: – C-, E-, S-class • System availability: Optional • Type of drive system: “4MATIC AWD with 4ETS” • Torque Split Front/Rear: Permanent 40/60 via center differential • 4ETS – M-class, G-class • System availability: Standard • Type of drive system: "Permanent full-time 4WD” • Torque Split Front/Rear: G-class: 50/50 via center differential • Torque Split Front/Rear: M-class: 48/52 via center differential • G-class: 3 locking differentials. 4ETS with unlocked differentials • M-class: Low range 2-foot mode; downhill traction function. 4ETS+

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What is “4ETS”? It is a system that: • is always in 4-wheel drive, without driver having to switch the system “on” • works with ABS and ASR in the Electronic Stability Program (ESP) to provide optimal handling stability and traction • distributes drive torque to the front and rear axle through a transfer case, which acts like a center differential. • uses brake pressure to control wheel spin, transferring torque to the wheel with traction • warns driver of wheel slip by flashing warning lamp in instrument cluster

6

Torque Application at the Wheels Having Traction

Wheels without traction are braked to transfer torque to the wheels with traction

7

In Comparison to 1990-1993 “4MATIC”:

• Ride height lower • Simpler front suspension • No additional hydraulics • Less intrusive to interior space (floorpan) • More cost-effective • Reduced weight • Better fuel mileage • Improved turning radius • Tire life extended

8

Driving With “4ETS” • Nothing to switch “on” • Driver is informed via a flashing warning lamp in instrument cluster that one or several wheels are starting to spin. (The owners manual says to ease off on the accelerator when this happens) • Throttle reduction control (ESP) can be switched off using “ESPOFF” button, but 4ETS continues to operate. Warning lamp stays illuminated in this mode.

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Additional 4ETS Components

• • • • •

Transfer case Propeller shaft, front Front differential – mounted to engine oil pan on right side Engine oil pan Front axle shafts – different length axles, but both ends identical

10

Passenger Car

Transfer Case

MY2004 components shown 8 Hexagon nut with collar 9 Hexagon nut with collar 10 Output flange to front axle 12 Output flange to rear axle 13 Output shaft to rear axle 15 Transfer case rear cover 16a Transfer case housing front 16b Transfer case housing rear

17 Output shaft to front axle 18 Intermediate gear 19 Hollow gear 20 Input shaft 20a Securing washer 20b Washer 20c Securing washer 25 Planetary gear set

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Passenger Car

Transfer Case Lubrication • Gears serve as an oil pump-oil ducts and splasher pipe supply lube oil to bearings and planetary gear system • Automatic Transmission Fluid (2004=001 989 2303) • Lifetime fill • For 2004: Check oil level at room temperature and not at transfer case operating temperature. 12

Passenger Car

Transfer Case Torque Distribution: MY1998-2002

3 = Double planetary gear set: acts as center differential

13

Passenger Car

Transfer Case Torque Distribution: Starting MY2004

60 % of the drive torque is transmitted to the rear axle and 40 % to the front axle.

1. Output shaft rear axle. 2. Double planetary gear set

3. 4. 5.

Spur gears Output shaft front axle Input shaft

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Passenger Car

Friction Disc in 2004 Planetary Gear Set

• To help quickly transfer torque to the front wheels when the rear starts to spin. • It is critical that 4ETS receives accurate wheel speed signals in order to properly control torque distribution. All 4 wheels / tires must have the exact same diameter and proper inflation pressures or the clutches will be damaged. • A worn disc would be noticed when driving in very slick conditions and comparing response with that of a known good vehicle. 15

Passenger Car

Transfer Case & Propeller Shafts

MY2004 components shown

1. 2. 3. 4.

Propeller shaft to rear axle Double planetary gear set Spur gears Propeller shaft to front axle

The transfer case is directly flange-mounted to the automatic transmission.

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Passenger Car

Front Wheel Drive Components MY2004 components shown

1. Transfer case 2. Propeller shaft to front axle gearbox 3. Front axle gearbox 4. Right front axle shaft 5. Left front axle shaft

The driveshaft has been carried over from model 210 4MATIC and has been modified in length

17

Passenger Car

Front Axle Open Differential Cutaway MY2004 components shown

Front axle gear box on model 220 with engine 113 1. Front axle gearbox mounted to oil pan 2. Pinion gear 3. Ring gear 4. Engine Oil Pan with cast-in through pipe

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Passenger Car

4ETS Brake Torque Control Range

A. Control of rear axle • Engages upon slippage in range of 0 to 50mph • Once engaged, control may remain active up to 80mph B. Control of front axle • Engages upon slippage in range of 0 to 25mph • Once engaged, control may remain active up to 50mph

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Passenger Car

4ETS Control Logic Traction control according to wheel speed • Low speeds: Individual brake application at any of the 4 wheels for maximum traction • Medium speeds: Limited brake pressure increase at the 2nd rear wheel if one rear wheel spins. Simultaneous pressure increase if both rear wheels spin. Stability and road adhesion take precedence. • High speeds: Simultaneous braking pressure to both rear wheels if one spins. At the same time the system refrains from any braking intervention at the front axle to achieve the best possible handling stability.

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Passenger Car

4-ETS Block Diagram Return pump Relay K40/

Power Circuit 31

Hydraulic control unit A7/

Terminal 61 Stop lamp switch

ETS warning lamp N47/

Parking Brake FRT VSS REAR VSS

ETS MIL ABS MIL Data Link (X11/4) 21

Passenger Car

Maintenance – MY2004 Transfer Case Check oil level – port 7b Filling with oil – port 7a The rear transverse mount (45) and the drive shaft must be removed. Draining oil – port 7c The rear mount (45) and the right case mount (45a) must be removed.

7a 7b 7c 16 45 45a

Fill port Control port Drain port Transfer case Rear case mount Right case mount

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Passenger Car

Maintenance – MY2004 Front Differential Check oil level – port 7 Oil level should be at lower level of fill port. Check oil level at room temperature - not at differential operating temperature. Right wheel well 7

Fill port

23

Passenger Car

Removing MY’04 Front Axle Shaft:

Wrap chain tool around constant velocity joint and tighten. Tap against chain to remove axle.

1 – extension or punch 2 – front axle shaft

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Reference: WIS job AR33.30-P-0620P

W163

Model W163 Starting MY1998 4ETS plus Hi/Low range

25

W163

W163

vs.

Passenger Cars

52%

60%

48% 40%

High/Low range motor Shift fork

Single speed range ------------

Chain drive Lubrication pump

Gear drive Splash lube

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W163

Off-Roading with the W163 • Possible to switch to Low range before driving off road, crossing water, or towing on steep grades. • Low range of transfer case provides a 2.64:1 ratio (High range = 1:1 ratio) • Off-road software in ABS improves braking when in Low Range under 18.5mph. Front wheel brakes only allowed to partially lock. (Helps by packing dirt in front of tires. Steering may be affected) • Switching into either Low or High transfer case range can be done only if all of the conditions on next slide are met 27

W163

High/Low Range Selection

Conditions: • Vehicle stopped • Selector in “N” • Idle (400-1500rpm)

High to Low – Lamp 2 flashes, then stays ON. Low to High - 2 flashes, turns Off. Conditions not met - flashes 5 times, 28 turns off.

W163

W163 Transfer Case & Controls • High/Low range motor (A55) • Control unit (N78) • Low Range Switch (S97/6)

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W163

High/Low Range

HIGH

LOW

Front gear set: selects High or Low range operation Rear double planetary gear set (center differential): distributes torque to front and rear differentials

30

W163

High Range

Low Range

1:1

2.64:1

1 – Input shaft 2 – Intermediate shaft 11 – Reduction hub 13 – Shift fork 18 – Planetary gear set 19 – Planetary carrier assy

31

W163

Transfer Case Control Unit (N78)

N78 retains DTCs while the ignition is on. All Activity Module (N10) stores the DTCs after ignition is switched off.

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W163

W163 Block Diagram CAN-C

Circuit 30 Circuit 15

Transmission Control module (N15/3

Circuit 31 “Low Range Switch” (S97/6) Transfer case actuator motor (A55)

Traction Control (N47/)

N78

ME-SFI (N3/10) AAM (N10)

X11/4

“Low Range Lamp” A1e46

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W163

W163 Service Notes • Transfer case is filled for life • ML transfer case must be in Hi range before disassembly • W163 transfer case has a total of 5 replaceable seals (items #22, 24 at each output shaft, 37, 44 on exploded view drawing) • 3 seals can be replaced without removing transfer case (#24 at rear, 37,44 on exploded view drawing) • Transfer case halves are sealed with silicone sealer only • Transfer case oil pump operates in forward gears only • Towing: MB recommends using flat bed equipment – When towing with all wheels on ground, place gear selector in “N”, ignition switch in position “2”, at a speed of = 30mph and towing distance = 30 miles. – See owners manual for more options/cautions

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W163

Transfer Case Exploded View

Legend on next pages

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W163

Legend Item No.

Description

Qty

Item No.

Description

Qty

Item No.

Description

Qty

01

Snap ring

1

05

Thrust washer

1

10

Ball brg

1

02

Ball bearing

1

06

Reduction hub

1

11

Ball brg suppt

1

03

Snap ring

1

07

Int.shaft compl

1

12

Retaining ring

1

04

Carrier compl.

1

07a

Int shaft

1

13

Diff ring gear

1

04a

Pinion shaft

3

07b

Bushing

1

14

Rr output shaft 1

04b

Planet carrier plate

1

08

Gerotor pump

1

15

Thrust washer

1

04c

Input shaft

1

08a

Cover

1

16

Carrier compl

1

04d

Needle brg

1

08b

Gear set

1

16a

Pinion shaft

6

04e

Thrust washer

1

08c

Pump body

1

16b

Thrust washer

12

04f

Planet carrier

1

08d

Bolt

4

16c

Pinion gear

6

04g

Thrust washer

6

08e

Hose

1

16d

Planet carrier

1

04h

Pinion gear

3

08f

Hose clamp

2

17

Spacer

1

04i

Needle brg

90

08g

Oil pickup & filter

1

18

Upper sprcket

1

04j

Pinion spacer

3

09

Thrust washer

1

18a

Upper drive

1

36

W163

Legend Item No.

Description

Qty

Item No.

Description

Qty

Item No.

Description

Qty

18b

Bushing

1

29

Ball brg

2

35

T-case cover

1

19

Spacer

1

30

Chain drive

1

36

1

20

Retng ring

1

31

Red. Shft fork

1

Companion flange

37

Oil seal

1

38

Washer

1

39

Stake nut

1

40

Drain plug

2

41

Motor bracket

1

42

Hex head bolt

3

21 21a

Case assy Transfer case

1 1

31a 31b

Shift fork facg Shift fork red.

2 1

21b

Ring red. gear

1

31c

Cam follower

1

21c

Retaining ring

1

31d

Shift fork pin

1

22

Oil seal

1

32

1

23

Lwr output shft

1

Shift shaft assy

32a

Shift shaft

1

24

Oil seal

2

43

Shift motor

1

32b

Spacer

1

25

Spring pin dwl.

2

44

Oil seal

1

32c

Torsion spring

1

26

Magnet

1

45

1

32d

Elect shift cam

1

Hex head screw

27

Ball brg.

1

33

Shift rail

1

46

ECU

1

28

Lower drive sprocket

1

34

Hex bolt

18

47

RTV

AR

37