General Information - Noise Diagnosis - Rear Axle

The most essential part of rear axle service, as with any mechanical repair, is proper diagnosis of the problem. In axle work, one of the most difficult areas to diagnose is noise. Any gear driven unit, especially a gear driven axle where engine torque occurs at a 90 degree angle, produces a certain amount of noise. An interpretation should be made for each vehicle to determine whether a noise is normal or if a problem actually exists. One way of determining this is road testing an identical vehicle with the same options under the same conditions. If the same amount of noise is audible at the same speeds and under the same conditions, it may be deemed commercially acceptable since it is unlikely that the exact same problem exists in both vehicles. A normal amount of noise must be expected and cannot be eliminated by conventional repairs or adjustments. However, if a noise proves to be extremely loud or unusual, then it should be investigated. This can be accomplished by a road test and a systematic check of the components associated with the rear axle to isolate the noise.