Rear Axle Noises

If a careful test of the vehicle shows that the noise is not caused by external items, it is then reasonable to assume that the noise is caused by the rear axle assembly. Test the rear axle by driving on a smooth level road to avoid road noise. Do not test the rear axle for noise by running with the rear wheels jacked up. Noise in the rear axle assembly may be caused by a faulty propeller shaft, faulty rear wheel bearings, faulty differential or pinion shaft bearings, misalignment between the two universal joints or worn differential side gears and pinions. Noise may also be caused by a mismatched, improperly adjusted or scored ring and pinion gear set.