GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

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

Loose propeller shaft mounting bolts

Tighten the bolts as required. Refer to Fastener Tightening Specifications .

Worn propeller shaft constant velocity joint

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 may cause vehicle vibration or a grinding, squealing type of noise.

Refer to Propeller Shaft Replacement .

Worn universal joints

Replace the universal joints as required. A worn universal joint may create a clicking or snapping type of noise.

Refer to Propeller Shaft Replacement .

Worn axle shaft constant velocity joints

Replace/repair the constant velocity joints as required. A worn axle shaft constant velocity joint may create a clicking, grinding, or snapping type of noise.

Refer to Symptoms - Rear Drive Axle .

Transfer case noise

For the NVG 900 Transfer Case, refer to Diagnostic Starting Point - Transfer Case.

For the Getrag 760 Transfer case, refer to Diagnostic Starting Point - Transfer Case.

Worn or damaged axle mounting bushings (side)

Replace bushings as required.

A worn bushing may create a clunk type of noise during acceleration or deceleration.

Refer to Differential Housing Support Bushing Replacement .

Worn or damaged axle mounting bushing (rear)

Replace bushings as required.

A worn bushing may create a clunk type of noise during acceleration or deceleration.

Check bushing orientation; the tuning slots must be in proper position.

Loose rear mounting bracket

Tighten the bracket bolts as required.

Refer to Fastener Tightening Specifications .

Loose or damaged prop guard

Repair or replace as required.

A loose dust shield may contact the propeller shaft assembly and create a scraping or grinding type of noise.

Bearing noise within axle assembly

A grinding roar type of noise will increase or decrease relative to the vehicle speed.

  1. Check for proper fluid level. Refer to Rear Axle Lubricant Replacement .
  2. If the noise continues, repair or replace the unit as required.

Gear set whine noise within axle assembly

A whine type of noise will increase or decrease relative to the vehicle speed, approximately 80-90 km/h (50-56 mph).

  1. Check for the proper fluid level. Refer to Rear Axle Lubricant Replacement .
  2. Repair or replace the unit as required.

Shutter or moan at slow speeds or slow turns

A shutter or moan type of noise in slow sharp turns.

  1. RDM could be contaminated with the wrong fluid type/water.
  2. Replace the fluid; fill as required and retest under conditions. Refer to Rear Axle Lubricant Replacement .
  3. Replace the drum.