Rear Wheel Bearings - Rear Axle

Rough or pitted rear wheel bearings can be responsible for a growling noise. The first impression of this growling noise could be suspected as a differential noise. The noise, however, does not vary on drive or coast. Additionally, the noise persists when coasting with the transmission in neutral. Frequently this noise can be readily identified by the sound being conveyed in an eccentric form. The noise can also be intermittent as the noise may fade for a short period. Perform the following steps to confirm the diagnosis of a rear wheel bearing noise:

1. Support the rear of the vehicle on safety stands.
2. Start the engine.
3. Disengage the traction control.
4. Raise the engine speed up to a fast idle with the top gear engaged.
5. Use a stethoscope to compare the noise of one bearing against the other.
6. Keep the volume adjustment down low to obtain the best results.
7. A difference in the noise of the rear wheel bearings can also by discerned by placing a steel-shafted screwdriver to the ear and in close proximity to each bearing in turn.

A noticeable difference in noise can usually be observed between a good and an excessively worn bearing.