Front Steering Knuckle: Service and Repair

31 21 090 - Removing and installing/replacing left or right swivel bearing





Special tools required:
- 31 2 230





Necessary preliminary tasks:
- Remove front brake disc 34 11 220 Removing and Installing/Replacing Both Front Brake Discs
- Remove front pulse generator from swivel bearing 34 52 525 Replacing One Front Pulse Generator

Important!
Check sensor head and line from pulse generator prior to installation for external damage, replacing if necessary.





If necessary, remove jointed rod of ride-height sensor from control arm.





Slacken control arm bolt connection on front axle carrier 31 12 000 Removing and Installing/Replacing Left or Right Control Arm in order to prevent control arm rubber mount from being overelongated.
Remove control arm from swivel bearing 31 12 000 Removing and Installing/Replacing Left or Right Control Arm.
Remove tie rod end from swivel bearing 32 21 151 Replacing Left or Right Tie Rod.

Warning!
Risk of injury!
Tension strut is under tension.

Remove tension strut from swivel bearing 31 12 080 Removing and Installing/Replacing Both Tension Struts





Support swivel bearing with workshop jack and a suitable mounting.
Release nut (1), remove holder (2) and remove screw.

Installation:
Screw head must point in direction of travel.
Replace self-locking nut.
Tightening torque 31 31 3AZ 31 31 Spring Struts (Front).





Spread swivel bearing with special tool 31 2 230.
Lower workshop jack and remove swivel bearing.

Installation:
Keep press fit of swivel gearing and spring strut in lower area clean and free from oil and grease.





Installation:
Expand swivel bearing with special tool 31 2 230, align by way of gap to positioning pins (1) on back of spring strut and raise up to stop.





Installation:
Make sure swivel bearing contacts stop (1) correctly.





Replacement:
- Modify wheel bearing 31 21 180 Replacing Bearing (Wheel Bearing) For Front Wheel or replace if necessary
- Modify brake carrier/brake guard plate 34 11 250 Replacing Front Left or Right Brake Anchor Plate/Guard Plate





After installation:
- Perform chassis alignment check
- Carry out steering angle sensor adjustment Adjustments