Table of contents: Replacing the rear wheel bearing.… ↓ Adjusting the rear wheel hub… ↓ Wheel hub bearings for all-wheel… ↓
When cornering with a loaded vehicle, the rear suspension level is adjusted hydraulically. In vehicles with adjustable suspension level, the power steering pump supplies the working fluid under high pressure to a special rear shock absorber until the body is raised to the normal level again. The amount of fluid needed is determined by a hydraulic level valve, which reads an electrical signal in the rear axle stabilizer bar, how much the rear of the vehicle is tilted. The more the rear of the vehicle is tilted, the more the valve opens. To avoid the risk of overloading the trunk, the valve only adjusts the level until the maximum load on the rear axle is reached. Therefore, when overloaded, the rear of the vehicle is lowered in spite of the level adjustment.
To prevent the body from lowering immediately after the engine stops, a hydraulic or pneumatic accumulator is connected to the shock absorbers, which increases the pressure in the shock absorber using compressed nitrogen. This hydraulic or pneumatic accumulator also acts to accept in working condition the working fluid that is displaced when the piston rod of the shock absorber is raised.
Note: The hydraulic level control system is still under high pressure even after the engine has stopped. Therefore, do not loosen the connections of the level control lines and hoses.
Replacing the rear wheel bearing. Front-wheel drive vehicles
When replacing a bearing, a new cotter pin, inner and outer bearing, and sealing ring are used.
Remove the brake drum (chapter "Brakes").
For cars with disc brakes, the rear brake discs are removed, including the wheel hub. To do this, remove the disc wheel brake bracket (chapter "Brakes"). The rest of the removal occurs in the same way as for brake drums.
Remove the sealing ring at the rear of the wheel hub, take out the bearings and wipe off the old grease from the bushing.
Knock the outer races of both bearings out of the wheel hub. To do this, use a brass punch, which is placed on the inside of the bearing race and knocked out with a hammer. Note that the races are not connected.
Install new outer bearing races into the wheel hub (thick side inward), so that no damage occurs during adjustment.
The rear shock absorber mounting points are almost identical for front-wheel drive and all-wheel drive vehicles.
Left: Shown here are the three upper mounting bolts (arrows).
Right: Shows the lower mounting bolt (arrow) for front-wheel drive vehicles.
Installing rear wheel bearings on front wheel drive vehicles.
Left: Removing the protective cap. Carefully insert the chisel behind the ring of the protective cap. Using careful hammer blows, knock the cap forward. Change the position of the chisel and do this several more times. Do not bend the cap.
Right: thrust washer (1) under nut (2) (here with the slotted stopper still installed) when the bearing clearance is adjusted correctly using a screwdriver, it should move slightly forward. The screwdriver slot should not rest on the brake disc.
Press the bearing races in until they stop, using the old race.
Now remove the old bearing race that was put on for protection.
Lubricate the gap between both bearing races, fill the races and bearings with grease.
Install the inner bearing.
Use a rubber hammer to evenly install the sealing ring on the inside.
Install the brake drum and disc accordingly.
Install the outer wheel bearing and thrust washer.
Tighten the lock nut by hand 1/8 turn; while doing this, constantly rotate the wheel so that the bearing does not jam.
Adjust the wheel bearing (see next section).
For vehicles with disc brakes, install the disc brake calipers at the rear. Then press the brake pedal repeatedly.
Adjusting the rear wheel hub bearings. Front-wheel drive models
Raise the rear of the vehicle and support it.
Remove the wheel cap, cotter pin and crown cap using the method described in the section "Removing the brake drum" in the chapter "Brake system".
Models with rear drum brakes: Press the adjusting wedge upwards as described in the above section. The brake drum will then rotate completely freely.
Tighten the hex nut without applying excessive force, while rotating the wheel to avoid jamming the bearings.
Loosen the nut slightly again.
The clearance is set correctly if you can slightly move the thrust washer behind the nut by lightly pressing with a screwdriver. The blade of the screwdriver should not rest against the edge of the wheel hub.
If it is still not possible to insert the locking pin into the locking retainer, then the nut needs to be turned slightly in the "close" direction.
Put on the wheel cap, tapping it with a rubber hammer, if necessary, put a tight roll of rags underneath.
Wheel hub bearings for all-wheel drive models
All-wheel drive models also have pressed-in double ball bearings on the rear axle. Although they do not need to be adjusted, due to the lack of press molds, they cannot be replaced independently.