Cause  | Correction  | 
|---|---|
Inspect for proper gear oil levels prior to performing system diagnosis.  | |
Low gear oil levels  | Faulty oil seal or other types of leaks may contribute to lower than required fluid levels. Refer to Rear Axle Lubricant Leak Diagnosis . Fill to the proper level with gear oil. Refer to Adhesives, Fluids, Lubricants, and Sealers .  | 
Worn or loose axle mounts  | Repair or replace axle mounts as required.  | 
Worn propeller shaft constant velocity or universal joints  | Replace the universal joints as required. Refer to Universal Joint Replacement - External Snap Ring in Propeller Shaft. If constant velocity joint is damaged, replace the propeller shaft. Refer to Propeller Shaft Replacement .  | 
Worn propeller shaft center bearing assembly  | Replace the center bearing assembly. Refer to Center Bearing Removal .  | 
Bearing noise within axle assembly  | This type of noise will decrease or increase relative to the vehicle speed. 
  | 
Gear set whine noise within the carrier assembly caused by incorrect backlash  | A whine type of noise will increase or decrease relative to the vehicle speed. 
  |