GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

Important: Inspect the differential oil level prior to performing system diagnosis. Refer to Rear Axle Lubricant Level Inspection.

Gear whine noise within Rear Drive Axle.

  1. If oil level is correct then check the condition of the oil. Drain and fill as required.
  2. If the oil is in good condition check for foreign particle contamination. Drain and fill as required.
  3. If the oil is not contaminated with foreign particles then check for water contamination. Drain and fill as required.
  4. If the oil is not contaminated with water, or if the noise continues, then road test the vehicle.
  5. If result of the road test confirms likely Rear Drive Axle noise, then repair or replace the unit as required. If result of a road test confirms likely that noise is not related to the Rear Drive Axle, then refer to relevant component subsection for further diagnosis.

Bearing noise within Rear Drive Axle.

  1. If oil level is correct then check the condition of the oil. Drain and fill as required.
  2. If the oil is in good condition check for foreign particle contamination. Drain and fill as required.
  3. If the oil is not contaminated with foreign particles then check for water contamination. Drain and fill as required.
  4. If the oil is not contaminated with water, or if the noise continues, then road test the vehicle.
  5. If result of the road test confirms likely Rear Drive Axle noise, then repair or replace the unit as required. If result of a road test confirms likely that noise is not related to the Rear Drive Axle, then refer to relevant component subsection for further diagnosis.