Constant Noise

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Inspect for the proper gear oil levels prior to performing system diagnosis. Refer to Rear Axle Lubricant Replacement .
Low gear oil levels	Faulty oil seal or other type external leaks may contribute to lower than required fluid levels. Refer to Rear Differential Carrier Leak Diagnosis . Fill to proper level with gear oil GM P/N 12378514 (Canadian P/N 88901045).
Worn, loose, or missing differential mounts	Repair or replace the differential mounts as required.
Worn propeller shaft constant velocity joints	Replace the propeller shaft assembly. Refer to Two-Piece Propeller Shaft Replacement .
Worn bearing in the torque tube assembly	Replace the torque tube assembly.
Bearing noise within the differential assembly A "grinding" or "roar" type noise will increase or decrease relative to the vehicle speed.	Check for the proper fluid level. Fill as required. If the noise continues, replace unit as required.
Gear set "whine" noise within the differential assembly A "whine" type noise will increase or decrease relative to the vehicle speed, approximately 80-97 km/h (50-60 mph).	Check for the proper fluid level. Fill as required. Replace unit as required.