GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Firebird 🢒 General Information 🢒 General Information 🢒 Rear Axle Housing Cover and Gasket Replacement

Removal Procedure
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle
  2. Clean all of the dirt from the area of the rear axle housing cover before removing the cover.

    3. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

  3. Remove the following components:
    4. • The rear axle housing cover bolts/screws
    • The parking brake cable guides
  4. Pry the rear axle housing cover loose.

    5. Remove the rear axle housing cover. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

  5. Drain the lubricant.
  6. Remove the rear axle housing cover gasket.

    7. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

  7. Clean both of the gasket sealing surfaces.

Installation Procedure
  1. Install a new rear axle housing cover gasket.

    2. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

  2. Install a new rear axle housing cover.

    3. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

  3. Install the park brake cable guides.

    4. 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.

  4. Install the rear axle housing cover bolts/screws (20 or 18).

    5. Refer to

    Rear Axle With Antilock Brake System (Drum Brakes)


    Object Number: 180427 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Wheel Speed Sensor
    (13)Rear Wheel Speed Sensor Bolt/Screw
    (14)Differential Drive Pinion Gear Inner Bearing
    (15)Differential Drive Pinion Gear Shim
    (16)Differential Drive Pinion Gear
    (17)Rear Axle Housing Cover Gasket
    (18)Rear Axle Housing Chip Collector Magnet
    (19)Rear Axle Housing Cover
    (20)Rear Axle Housing Cover Bolt/Screw
    (21)Rear Brake Backing Plate Nut
    (22)Rear Wheel Bearing
    (23)Rear Wheel Bearing Seal
    (24)Rear Brake Backing Plate
    (25)Rear Brake Backing Plate Bolt/Screw
    (26)Rear Axle Shaft Lock
    (27)Rear Axle Shaft
    (28)Rear Wheel Bolt
    (29)Rear Brake
    (30)Rear Brake Drum
    or

    Rear Axle With Antilock Brake and Traction Control Systems
    Object Number: 180429 Size: LF
    (1)Differential Drive Pinion Gear Nut
    (2)Differential Drive Pinion Gear Washer
    (3)Differential Drive Pinion Gear Yoke
    (5)Differential Drive Pinion Gear Dirt Deflector
    (6)Differential Drive Pinion Gear Seal
    (7)Differential Drive Pinion Gear Outer Bearing
    (8)Differential Drive Pinion Gear Bearing Spacer
    (9)Rear Axle Housing Drain Plug
    (10)Rear Axle Housing
    (11)Rear Axle Vent
    (12)Differential Drive Pinion Gear Inner Bearing
    (13)Differential Drive Pinion Gear Shim
    (14)Differential Drive Pinion Gear
    (15)Rear Axle Housing Cover Gasket
    (16)Rear Axle Housing Chip Collector Magnet
    (17)Rear Axle Housing Cover
    (18)Rear Axle Housing Cover Bolt/Screw
    (19)Rear Brake Backing Plate Nut
    (20)Rear Wheel Bearing
    (21)Rear Wheel Bearing Seal
    (22)Rear Axle Tube Flange Shim
    (23)Rear Brake Caliper Bolt/Screw
    (24)Rear Brake Caliper Mounting Plate
    (25)Rear Brake Caliper Mounting Plate Bolt/Screw
    (26)Wheel Speed Sensor
    (27)Rear Brake Caliper
    (28)Rear Axle Shaft Lock
    (29)Rear Axle Shaft
    (30)Rear Wheel Speed Sensor Reluctor Wheel
    (31)Rear Wheel Bolt
    (32)Rear Brake Rotor

    Tighten
    Tighten the rear axle housing cover bolts/screws (20 or 18) in a crosswise pattern to 30 N·m (22 lb ft).

  5. Fill the lubricant. Refer to Lubricant Level Check
  6. Lower the vehicle.