Cause  | Correction  | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Inspect for the proper gear oil levels prior to performing system diagnosis.  | |||||||||
Loose propeller shaft constant velocity joints  | Tighten the bolts, as required. Refer to Propeller Shaft Replacement.  | ||||||||
Worn propeller shaft constant velocity joints  | Replace the propeller shaft assembly. Refer to Propeller Shaft Replacement. A worn propeller shaft constant velocity joint may create a clicking, grinding, or snapping type noise.  | ||||||||
Worn or loose center bearing assembly  | Replace the center bearing assembly, as required. A worn center bearing assembly may cause vehicle vibration or a grinding or squealing type noise.  | ||||||||
Worn universal joints  | Replace the universal joints, as required. A worn universal joint may create a clicking or snapping type noise.  | ||||||||
Worn axle shaft constant velocity joints  | Replace/repair the constant velocity joints, as required. A worn axle constant velocity joint may create a clicking, grinding, or snapping type noise.  | ||||||||
Rear axle noise  | |||||||||
Loose mounting bracket  | Tighten the bracket bolt or replace the bracket, as required.  | ||||||||
Loose transfer case-to-transmission mounting bolts  | Tighten the bolts, as required.  | ||||||||
Incorrect gear oil  | Replace with synthetic gear oil GM P/N 12378514 (Canada P/N 88901045).  | ||||||||
Bearing noise within the transfer case  | A grinding or roar type noise will increase or decrease relative to the vehicle speed. 
 
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Gear set whine noise within the transfer case  | Whine type noises will increase or decrease relative to the vehicle speed, approximately 80-90 km/h (50-60 mph). 
 Contributing factors may include: 
 
 
 
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