GM Service Manual Online
For 1990-2009 cars only

Rear Axle Lubricant Replacement 8.6 Inch Axle

Removal Procedure

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .

  2. Object Number: 392774  Size: SH
  3. Remove the rear axle fill plug.

  4. Object Number: 341650  Size: SH
  5. Remove the rear axle housing cover bolts (1). Discard the rear axle housing cover bolts.
  6. Carefully remove the rear axle housing cover (2) and drain the lubricant into a suitable container.
  7. Remove any gasket material from the rear axle housing and/or the rear axle housing cover.
  8. Inspect the bottom of the rear axle housing for excessive metal particle accumulation. This accumulation is an indication of extreme wear.

Installation Procedure


    Object Number: 341650  Size: SH
  1. Install a new gasket and the rear axle housing cover (2).
  2. Notice: Refer to Fastener Notice in the Preface section.

    Important: Do not reuse the rear axle housing cover bolts.

  3. Install the new rear axle housing cover bolts (1).
  4. Tighten
    Tighten the bolts to 40 N·m (30 lb ft).

  5. Fill the rear axle. Use the proper fluid. Refer to Approximate Fluid Capacities and Fluid and Lubricant Recommendations .

  6. Object Number: 392774  Size: SH
  7. Install the rear axle fill plug.
  8. Tighten
    Tighten the rear axle fill plug to 33 N·m (24 lb ft).

  9. Lower the vehicle.

Rear Axle Lubricant Replacement 9.5, 10.5,and 11.5 Inch Axles

Removal Procedure

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  2. Object Number: 392774  Size: SH
  3. For the 9.5 inch and the 10.5 inch axles, remove the rear axle fill plug.

  4. Object Number: 665917  Size: SH
  5. For the 11.5 inch axle, remove the fill plug.

  6. Object Number: 390113  Size: SH
  7. Remove the rear axle drain plug.
  8. Drain the lubricant into a suitable container.
  9. Inspect the drain plug for excessive metal particle accumulation. This accumulation is symptomatic of extreme wear.
  10. Clean the drain plug.

Installation Procedure

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


    Object Number: 390113  Size: SH
  1. Install the rear axle drain plug.
  2. Tighten
    Tighten the rear axle drain plug to 33 N·m (24 lb ft).

  3. Fill the rear axle. Use the proper fluid. Refer to Approximate Fluid Capacities and Fluid and Lubricant Recommendations in Maintenance and Lubrication.

  4. Object Number: 392774  Size: SH
  5. For the 9.5 inch and the 10.5 inch axles, install the rear axle fill plug.
  6. Tighten
    Tighten the rear axle fill plug to 33 N·m (24 lb ft).


    Object Number: 665917  Size: SH
  7. For the 11.5 inch axle, install the seal and the fill plug.
  8. Tighten
    Tighten the rear axle fill plug to 33 N·m (24 lb ft).

  9. Lower the vehicle.

Rear Axle Lubricant Replacement 9.75 Inch Axle

Removal Procedure

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  2. Object Number: 815459  Size: SH
  3. Remove the rear axle fill plug.

  4. Object Number: 390113  Size: SH
  5. Remove the rear axle drain plug.
  6. Drain the lubricant into a suitable container.
  7. Inspect the drain plug for excessive metal particle accumulation. This accumulation is symptomatic of extreme wear.
  8. Clean the drain plug.

Installation Procedure

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


    Object Number: 390113  Size: SH
  1. Install the rear axle drain plug.
  2. Tighten
    Tighten the rear axle drain plug to 27 N·m (20 lb ft).

  3. Fill the rear axle. Use the proper fluid. Refer to Approximate Fluid Capacities and Fluid and Lubricant Recommendations in Maintenance and Lubrication.

  4. Object Number: 815459  Size: SH
  5. Install the rear axle fill plug.
  6. Tighten
    Tighten the rear axle fill plug to 21 N·m (15 lb ft).

  7. Lower the vehicle.