Remove/install front axle gear

AR33.30-P-0525RT

Remove/install front axle gear

13.02.2019

Model

251

with 4MATIC

Modification notes

02.02.2011

"Final torque at K0 design level" added

Operation step 10

Shown on the left side of a vehicle with AIRmatic (air suspension with level adjustment and Adaptive Damping System (ADS)), code 489

2

Steering knuckle cable tie

5

Clips

3

Brake hose bracket

6

Clips

4

Brake hose retaining tab

Shown on the left side of a vehicle with AIRmatic (air suspension with level adjustment and Adaptive Damping System (ADS)), code 489

8

Nut, steering knuckle to upper transverse control arm

14

Tie rod

9

Steering knuckle

15a

Left drive shaft

10

nut, tie rod to steering knuckle

16

Screw

11

Upper transverse control arm

17

Left shock-absorber strut

12

Puller

18

Base

13

Puller

Shown on the right side of a vehicle with AIRmatic (air suspension with level adjustment and Adaptive Damping System (ADS)), code 489

7

Extraction and insertion tool

15b

Right drive shaft

19

Propeller shaft

22

Right screw at front axle carrier

20

Screws, propeller shaft to front axle transmission

23

Front axle transmission

21

Left screws on front axle carrier

 

Remove/install

 Danger

Risk of death caused by vehicle slipping or toppling off of the lifting platform.

Align vehicle between vehicle lift columns and position the four support plates at the vehicle lift support points specified by the vehicle manufacturer.

AS00.00-Z-0010-01A

Topical note

Notes on installing brake hoses

AH42.10-P-9406-01A

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

1

When working on the front-end assembly, be careful not to scratch, mark or notch the surfaces of aluminum parts. Otherwise the service life of the parts will be affected

2

Raise vehicle using two-post lift

AR00.60-P-1000RT

 Until the wheels are free of the ground.

3

Remove front wheels



AP40.10-P-4050RT

4

Unscrew front axle shaft collar nut

 Only on right hand side of vehicle.

 For counterholding purposes an assistant must apply the brake.

 Collar nut, front axle shaft to front axle shaft flange

*BA33.30-P-1001-02E

5

Raise vehicle using two-post lift

AR00.60-P-1000RT

 Raise to half height.
Two-post lifting platform, 3.0 - 3.5 t electromechanical,

6

Cut through steering knuckle cable tie (2) and remove together with brake hose retaining tab (4)

 On both sides of the vehicle.

 Installation: Pay attention to installation position.

 Installation: Replace steering knuckle cable tie (2).

 Pliers

*164589013700

7

Open brake hose bracket (3) and unclip brake hose

 On both sides of the vehicle.

8

Unclip electrical lines from retaining clips (5, 6)

 On both sides of the vehicle.

9

Press upper transverse control arm (11) out of steering knuckle (9)

 On both sides of the vehicle.

 Self-locking nut, upper ball joint out of upper transverse control arm to steering knuckle

*BA33.20-P-1001-01L

 Thrust piece

*140589006300

 Puller

*601589043300

10

Press right tie rod (14) out of right steering knuckle (9)

 On both sides of the vehicle.

 Self-locking nut, tie rod to steering knuckle

*BA46.40-P-1002-01L

 Thrust piece

*140589006300

 Puller

*140589093300

11

Release left shock-absorber strut (17) from lower transverse control arm

 Installation:
Final torque when vehicle is on measuring platform or at K0 design level.
In order to prevent placing rubber bushing under stress.

 Only on left-hand side of the vehicle.

 Self-locking nut, shock absorber to wishbone

*BA32.25-P-1002-01H

12

Fold steering knuckle (9) outwards and pull left drive shaft (15a) out of front axle differential (23)

 Only on left-hand side of the vehicle.

 The left drive shaft (15a) is not pressed out of the steering knuckle (9).

 Swivel left shock-absorber strut (17) upwards until inner flange of left drive shaft (15a) can be swiveled forward and be placed on a soft mat (18). Swivel left shock-absorber strut (17) down again; this prevents the left drive shaft (15a) from falling down and being damaged.

 Collect any oil which runs out.

13

Detach steering knuckle (9) from right drive shaft (15b)

 Only on right hand side of vehicle.

 Extraction and insertion tool

*210589034300

14

Fold steering knuckle (9) outwards and pull right drive shaft (15a) out of front axle differential (23)

 Only on right hand side of vehicle.

 The right drive shaft (15b) cannot be removed.

 Secure right drive shaft (15b) to steering knuckle (9) with a cable tie for example.

 Collect any oil which runs out.

15

Raise vehicle using two-post lift

AR00.60-P-1000RT

 Fully raise.

16

Remove bottom section of soundproofing

AR94.30-P-5300RT

 Only on vehicles with diesel engine.

17

Mark position of propeller shaft (19) relative to flange of front axle transmission (23)

18

Remove propeller shaft screws from front axle differential (20)

Model 251 (except 251.021/026/054/056/126/154/156)

AR41.10-P-0070-03GZ

 Installation:
Tightening specifications must be strictly observed.
Otherwise this may lead to noise development and vibrations.

 Self-locking bolt, propeller shaft to front axle gear

*BA41.10-P-1004-01G

 Retainer wrench

*164589020700

19

Support front axle transmission (23)

20

Remove screws at left of front axle carrier (21) and screw at right of front axle carrier (22)

 Collar bolt, front axle gear to left front axle carrier

*BA33.30-P-1002-02E

 Collar bolt, front axle gear to right front axle carrier

*BA33.30-P-1003-02E

21

Tilt front axle differential (23) out of mounts on front axle carrier and remove

 Collect any oil which runs out.

22

Install in the reverse order



Check

23

Check oil level in front axle gear (23) and top up if necessary

 If a new front axle differential (23) was installed, or in the event of oil loss after repair work, or if oil escaped during removal.

 Replace sealing ring of oil filler screw.

 Oil filler screw, front axle transmission

*BA33.30-P-1001-03E

 Filling capacity

*BF33.30-P-1001-03E

 Front axle shock absorber

Number

Designation

Model 251

BA32.25-P-1002-01H

Self-locking nut, shock absorber to wishbone

Nm

265

 Wheel control, hub

Number

Designation

Model 251

BA33.20-P-1001-01L

Self-locking nut, upper ball joint out of upper transverse control arm to steering knuckle

Stage 1

Nm

20

Stage 2

°

90

 Front axle shaft

Number

Designation

Model 251

BA33.30-P-1001-02E

Collar nut, front axle shaft to front axle shaft flange

Stage 1

Nm

250

Stage 2

°

45

 Front axle gear

Number

Designation

MODEL 251

Model 251 left-hand drive vehicle, except code 494

BA33.30-P-1001-03E

Oil filler screw, front axle transmission

Nm

35

35

 Front axle shaft

Number

Designation

Model 251

BA33.30-P-1002-02E

Collar bolt, front axle gear to left front axle carrier

Nm

93

 Front axle shaft

Number

Designation

Model 251

BA33.30-P-1003-02E

Collar bolt, front axle gear to right front axle carrier

Nm

50

 Propeller shaft

Number

Designation

Model 251

BA41.10-P-1004-01G

Self-locking bolt, propeller shaft to front axle gear

Stage 1

Nm

40

Stage 2

°

90

 Tie rod

Number

Designation

Model 251

BA46.40-P-1002-01L

Self-locking nut, tie rod to steering knuckle

Stage 1

Nm

45

Stage 2

°

90

 Front axle gear

Number

Designation

Model 251

BF33.30-P-1001-03E

Filling capacity

Front axle gear

Liter

1,1

Sheet

BB00.40-P-0235-07A