GM Service Manual Online
For 1990-2009 cars only

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

Refer to Diagnostic Starting Point - Transfer Case.

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.

    • Inspect for proper fluid level. Fill, as required.
    • If the noise continues, replace the unit.

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).

  1. Inspect for proper fluid level. Fill, as required.
  2. If the noise continues, repair or replace the internal components, as required.
  3. Contributing factors may include:

    • Incorrect backlash between the gear sets
    • Worn or damaged gear teeth
    • Transaxle assembly noise
    • Rear axle noise