Remove and install wheel hub/wheel bearing

A defective wheel bearing causes rolling noises and excessive play. The wheel bearing is not adjustable and cannot be replaced separately. If the wheel bearing is defective, the complete wheel hub must be replaced.

The illustration shows a section through the rear wheel hub.

1. 1

   Rim

2. 2

   Brake drum

3. 3

   Wheel hub

4. 4

   Wheel bearing

5. 5

   Axle nut

6. 6

   Wheel bolt

• Mark the position of the rear wheels relative to the wheel hub with paint.

  This allows the balanced wheel to be refitted in the same position. Loosen the wheel bolts. The vehicle must be standing on the ground.

  Raise the front of the vehicle on stands and remove the rear wheels.

• Carefully press the grease cap (hub cover) off the wheel hub. The grease cap can be removed using various tools, but care must be taken not to damage it.

  A dented or deformed grease cap can allow water into the wheel bearing, destroying it within a short time. Always replace a damaged grease cap.

• Refit the rear wheels and lower the vehicle.

  Apply the parking brake.

• Loosen the axle nut on the wheel hub with a SW32 socket. If necessary, hold the axle spindle from the rear with an 18 mm Allen key. Caution: The vehicle must be standing on the ground, risk of accident due to high torque. The axle nut must be replaced every time it is loosened.

• Release the parking brake, raise the vehicle and remove the rear wheels.

• Remove the brake drum - 1 - with its 2 retaining screws - 2 - and take it off.

• Remove the axle nut and pull the wheel hub with wheel bearing off the axle spindle. If necessary, use a commercially available puller.

• Before installing the wheel hub, visually inspect the axle spindle. It must not show cracks, deformation or signs of wear; otherwise the complete trailing arm must be replaced.

• Press the wheel hub with wheel bearing onto the axle spindle. Do not forget the spacer rings in front of and behind the bearing.

  Tighten the nut firmly. Caution: Make sure no brake dust gets onto the axle spindle or into the wheel bearing.

  Dirt that has entered will destroy the bearing over time.

• Fit the brake drum and tighten with 2 screws to 10 N·m.

• Fit the rear wheels so that the marks made during removal line up. Beforehand, lightly grease the centering seat of the rim on the wheel hub and the conical surface of the wheel bolts with wheel bearing grease. Do not grease or oil the threads of the wheel bolts. Install the wheels.

  Lower the vehicle and tighten the wheel bolts crosswise to 90 N·m.

• Tighten the wheel hub with a new retaining nut to 280 N·m. Warning: risk of accident due to high torque! Use only a stable torque wrench.

  The vehicle must be standing on the ground when tightening.

• Fill the grease cap with commercially available lithium grease, e.g.

  Tutela MR3. Wipe the edge of the grease cap with a clean cloth and carefully drive on the hub cap.

  Instead of the Fiat special tool, a suitable tube can also be used. The inside diameter of the tube must fit against the bead of the grease cap.

  If necessary, carefully drive on the hub cap with a rubber mallet. If the grease cap is deformed even slightly, it must be replaced.