Rear Wheel Bearing Replacement - Steel Trailing Arm

Introduction

Thanks to Ben Davis for the photographs documenting this procedure.

Tools

• 36 mm socket
• 8 mm cheesehead (triple-square) tool
• Metric socket set
• Phillips head screwdriver
• Jack stands
• Floor jack
• Gear puller or block of wood and hammer (for removing the stub axle)
• Seal puller
• Soft drift and hammer (for driving out wheel bearings)

Component Overview

1. Outer seal
2. Trailing arm mount
3. Stub axle
4. Outer bearing inner race
5. Inner bearing spacer
6. Inner bearing seal
7. Snap ring
8. Inner bearing
9. Spacer tube
10. Outer bearing
11. Trailing arm

Procedure

Note: The hardest part of this job is removing the axle nut, which is torqued to 350 ft-lbs. Rust build-up on the threads can require significantly more force. If even a 4-foot breaker bar with two people cannot break it free, a shop with a 3/4-inch drive impact wrench is the practical alternative.

1. Set the emergency brake to resist axle rotation during nut removal.

2. Loosen the rear wheel lug nuts several turns.

3. Raise that side of the vehicle with a floor jack.

4. Remove the lug nuts and rear wheel.

5. Remove the cotter pin for the axle.

6. Loosen and remove the axle nut: a. First try with an appropriate socket (32 mm or 36 mm depending on vehicle) and a long breaker bar. If it releases easily, proceed to Step 7. b. Place the socket on the axle nut — use an impact socket, as standard sockets can be destroyed by the torque required. c. Attach a breaker bar at least 24 inches long, parallel to the ground, with the handle end resting on a jack stand. For the left wheel the bar must point toward the rear; for the right wheel toward the front.

   Note: Position the breaker bar and jack stand to avoid contacting suspension or body when the car is lowered.

   d. Slowly lower the floor jack until the car's weight breaks the nut free. e. If this still fails, a 3/4-inch drive impact wrench is required.

7. Remove rear wheel spacers if fitted (most early 944s).

8. Remove the rear brake caliper.

9. Release the emergency brake.

10. Using a Phillips head screwdriver, remove the brake rotor retaining screws.

11. Remove the rotor. If stubborn, thread two M8 bolts into the provided holes and alternate tightening them to jack the rotor off the hub. Also remove the parking brake pads, spreader, and brake dust guard (four 19 mm hex head bolts).

12. Remove the rear hub.

13. Using the 8 mm cheesehead tool, disconnect the CV joint from the trailing arm and hang the axle out of the way.

14. Remove the stub axle using a gear puller or by driving it out with a block of wood and hammer. The inner spacer ring should come off with the stub axle; if it sticks to the inner bearing seal, remove it separately and inspect for scoring.

15. Remove the inner and outer bearing seals using a seal puller.

16. Remove the snap ring next to the inner wheel bearing.

17. Using a soft drift and hammer from the outside of the trailing arm, tap evenly around the inner wheel bearing to drive it out.

18. From inside the trailing arm, tap on the outer wheel bearing with the drift and hammer to drive it out evenly.

19. Remove the bearing spacer tube from the trailing arm and clean out all old grease.

20. Pack both new bearings with grease.

21. Install the new inner bearing using a socket as a driver or a soft-face hammer. Drive it in evenly and ensure the chamfered edge faces outward (away from the center of the trailing arm).

22. Install the snap ring next to the inner bearing.

23. From the outside of the trailing arm, pack fresh grease into the bearing cavity. Do not fill completely — leave room for the bearing spacer and for grease expansion.

24. From the outside, install the bearing spacer tube.

25. Using a socket and hammer, tap the outer bearing into the trailing arm. The chamfered edge must face outward.

26. Install the inner and outer bearing seals. Install the brake dust guard, parking brake pads, and spreader.

27. Install the stub axle. Ensure the inner spacer ring is on the stub axle before inserting it into the trailing arm.

28. Install the hub and axle nut. Torque the axle nut to 350 ft-lbs and install the cotter pin.

29. Install the brake rotor and secure with the Phillips head screws.

30. Adjust the parking brakes (see BRAKE-05).

31. Install the brake caliper and pads. Pump the brakes before driving.

32. Install the rear wheel spacer (if applicable) and rear wheel.

33. Lower the vehicle.

34. Repeat the above steps for the other side if needed.