GM Service Manual Online
For 1990-2009 cars only

Many noises that appear to come from the transaxle may actually originate with other sources such as the tires, road surfaces, wheel bearings, or the engine and exhaust system.

Identify the cause of any noise before attempting to repair the clutch, the transaxle, or their related linkages.

To verify suspected transaxle noises,

  1. Select a smooth, level asphalt road to reduce tire and resonant body noise.
  2. Drive the vehicle far enough to warm up all the lubricants thoroughly.
  3. Record the speed and the gear range of the transaxle when the noise occurs.
  4. Check for noises with the vehicle stopped, but with the engine running.
  5. Warning: Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.

  6. Determine if the noise occurs while the vehicle operates in the following:
  7. • Drive -- Under a light acceleration or a heavy pull.
    • Float -- Maintaining a constant speed with a light throttle on a level road.
    • Coast -- With the transaxle in gear and the throttle partly or fully closed.
    • All of the above

Checking Bearing Noise

Differential Side Bearing Noise

Differential side bearing noise and wheel bearing noise can be confused easily. Since side bearings are pre-loaded, a differential side bearing noise should not diminish much when the differential/transaxle is run with the wheels off the ground.

Wheel Bearing Noise

Wheel bearings produce a rough growl or grating sound that will continue when the vehicle is coasting and the transaxle is in NEUTRAL. Since wheel bearings are not pre-loaded, a wheel bearing noise should diminish considerably when the wheels are off the ground.

Checks

Actions

Insufficient Lubricant

Supply the lubricant.

Worn Input Shaft Gear

Replace the gear.

Worn Bearings on the Input Shaft Gears

Replace the bearing.

Worn Clutch Release Bearing

Replace the clutch release bearing.

Worn Bearings on the Input Shaft or Counter Shaft

Replace the bearing.

Worn Input Shaft or Counter Shaft Gear

Replace the gear.

Worn or Damaged Synchronizer Ring

Replace the synchronizer ring.

Worn or Damaged Synchronizer Sleeve

Replace the synchronizer sleeve.

Worn Differential Gear or Bearing

Replace the gear or bearing.

Worn or Damaged Synchronizer Ring in the selected GearRange

Replace the synchronizer ring.

Worn or Damaged Gear in the selected Gear Range

Replace the gear.

Worn or Damaged Bearing in the selected Gear Range

Replace the bearing.