Remove/install steering knuckle

AR33.25-P-0400RT

Remove/install steering knuckle

11.02.2019

Model

251

Modification notes

20.12.2007

Value changed: Collar nut, front axle stub to wheel hub, 1st stage

BA33.20-P-1010-01L

01.01.1970

Value changed: Collar nut, front axle stub to wheel hub, 2nd stage

BA33.20-P-1010-01L

01.01.1970

Value changed: Collar nut, front axle shaft to wheel hub, 1st stage

BA33.30-P-1001-02E

01.01.1970

Value changed: Collar nut, front axle shaft to wheel hub, 2nd stage

BA33.30-P-1001-02E

Shown on vehicle with AIRMATIC (air suspension with level adjustment and adaptive damping system ADS), code 489

1

Bracket

5

Cover panel

9

Tie rod joint

2

Brake caliper

6

Brake disk

10

Front axle shaft

3

Upper ball joint

7

Hexagon collar nut

L6/1

Left front rpm sensor

4

Steering knuckle

8

Supporting joint

L6/2

Right front rpm sensor

 

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

Notes on AIRmatic

AH32.22-P-1000-02RT

1

Raise vehicle

AR00.60-P-1000RT

 Until the wheels have ground clearance.

2

Deflate air springs with STAR DIAGNOSIS



AD00.00-P-2000-04A

 For vehicles with AIRMATIC (Air suspension with level adjustment and Adaptive Damping System (ADS)), code 489.

3

Remove front wheel



AP40.10-P-4050RT

4

Unscrew hexagon collar nut (7)

 On vehicles without 4MATIC when replacing the steering knuckle and on vehicles with 4MATIC.

 Let service brake be operated.

 Installation: Replace hexagon collar nut (7).

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

*BA33.30-P-1001-02E

 Collar nut, front axle stub to wheel hub

*BA33.20-P-1010-01L

5

Check supporting joint (8)

Check rubber boot and ball joint for wear and damage. Check play:



Check supporting joint (8)

AR33.20-P-0429RT

6

Remove left front rpm sensor (L6/1) or right front rpm sensor (L6/2)

 Self-locking bolt, front axle rpm sensor to steering knuckle

*BA42.30-P-1001-01I

7

Loosen holder (1) from steering knuckle (4)

 Installation: Pay attention to installation position.

 Installation: Replace cable tie.

 Pliers

*164589013700

8

Remove brake caliper (2), secure to upper transverse control arm in connected state, remove brake disk (6)

AR42.10-P-0220RT


The brake hose must not be kinked or twisted too much
because otherwise it may be damaged.

9

Loosen tie rod joint (9) from steering knuckle (4) and pry off.

AR46.40-P-0200-02RT

 Counterhold at bolt of tie rod joint (9).

 Self-locking nut, tie rod to steering knuckle

*BA46.40-P-1002-01L

 Thrust piece

*140589006300

 Puller

*221589003300

 Press

*163589034300

Check rubber boot and ball joint; if necessary, replace tie rod with tie rod joint (9):



Remove/install tie rod.

AR46.40-P-0200RT

10

Loosen upper ball joint (3) from steering knuckle (4) and pry off.

 Counterhold at bolt of upper ball joint (3).

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

*BA33.20-P-1001-01L

 Thrust piece

*140589006300

 Puller

*221589003300

 Press

*163589034300

Check rubber boot and upper ball joint (3); if necessary, replace upper transverse control arm with upper ball joint (3):



Remove/install upper transverse control arm (left)

AR33.20-P-0500RT

Remove/install upper transverse control arm (right)

AR33.20-P-0500RTA

11

Press front axle shaft (10) out of wheel hub

 On vehicles with 4MATIC.

 Extraction and insertion tool

*210589034300

12

Unfasten supporting joint (8) from lower control arm; remove steering knuckle (4)

 Counterhold at bolt of supporting joint (8).

 Support steering knuckle (4).

 Self-locking nut, lower transverse control arm to steering knuckle

*BA33.20-P-1003-01L

13

Remove cover panel (5)

 When replacing the steering knuckle (4).

14

Press supporting joint (8) out of steering knuckle (4)

Pressing out and attaching supporting joint at steering knuckle

AR33.20-P-0440-01GZ

 If the rubber boot and/or supporting joint (8) are damaged/worn.

 Locking slotted nut, supporting joint to steering knuckle

*BA33.20-P-1007-01L

 Removal and installation tool

*164589034300

 Claw wrench

*385589000700

 Hand pump

*652589003321

 Hollow cylinder

*652589003322

 Hydraulic hose (complete)

*652589003323

15

Press front axle stub out of steering knuckle (4)

 On vehicles without 4MATIC when replacing the steering knuckle (4).

 Extraction and insertion tool

*210589034300

16

Install in the reverse order

 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

 Wheel control, hub

Number

Designation

Model 251

BA33.20-P-1003-01L

Self-locking nut, lower transverse control arm to steering knuckle

Nm

230

 Wheel control, hub

Number

Designation

Model 251

BA33.20-P-1007-01L

Locking slotted nut, supporting joint to steering knuckle

Nm

300

 Wheel control, hub

Number

Designation

Model 251

BA33.20-P-1010-01L

Collar nut, front axle stub to wheel hub

Stage 1

Nm

250

Stage 2

°

45

 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 rpm sensor

Number

Designation

Model 251

BA42.30-P-1001-01I

Self-locking bolt, front axle rpm sensor to steering knuckle

Nm

8

 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