Inspect for the proper gear oil levels prior to performing system diagnosis.

Low gear oil levels

Faulty oil seal or other type leaks may contribute to lower than required fluid levels.

Fill to proper level with gear oil GM P/N United States 12378514, GM P/N Canada 88901045.

Worn or loose axle mounts

Repair or replace the axle mounts as required.

Worn propeller shaft constant velocity or universal joints

Replace the constant velocity or universal joints as required.

Refer to Propeller Shaft Disassembly in Propeller Shaft.

Worn propeller shaft center bearing assembly

Replace the center bearing assembly.

Bearing noise within the axle assembly

This type noise will increase or decrease relative to the vehicle speed.

1. Check for the proper fluid level. Fill as required.
2. Repair or replace unit as required.

Gear set whine noise within the carrier assembly caused by incorrect backlash

A whine type noise will increase or decrease relative to the vehicle speed.

1. Check for the proper fluid level. Fill as required.
2. Repair or replace unit as required.