Installation Procedure

2008 Pontiac Grand Prix BaseSECTION Installation Procedure
WARNING: This page is about a different car, the 2008 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
  1. Install the ring gear, if necessary. Refer to Drive Pinion and Ring Gear Replacement .
  2. Install the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement .
  3. Lubricate the differential side bearings with axle lubricant. Use the proper fluid. Refer to Fluid and Lubricant Recommendations .
  4. Fig 1: View Of Differential Case And Axle Housing
    GM667660Courtesy of GENERAL MOTORS CORP.
  5. Install the differential assembly into the axle housing by performing the following steps:
    1. Position the locking differential coil assembly wiring harness towards the rear axle housing cover, parallel to the drive pinion.
    2. Place the case, with the bearing cups installed, into the axle housing.

      Support the case in order to keep the case from falling out of the axle housing.

    3. If the differential assembly cannot be installed, turn the differential side bearing adjuster nut into the axle housing until the differential assembly can be installed.
    4. Route the wiring of the locking differential coil assembly away from the left side differential bearing cap mounting surface.
  6. Fig 2: Removing/Installing Bearing Cap Bolt
    GM667502Courtesy of GENERAL MOTORS CORP.
  7. Install the bearing caps and the bolts.

    Do not torque the bearing cap bolts at this time.

  8. Adjust the differential side bearing preload. Refer to Differential Carrier Bearing Preload Adjustment .
  9. Adjust the backlash. Refer to Backlash Adjustment .
  10. Once backlash and bearing preload is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection .
  11. Fig 3: Left Side Differential Bearing Bolts
    GM841742Courtesy of GENERAL MOTORS CORP.
  12. Remove the left side bearing cap bolts.
  13. Remove the left side bearing cap.
  14. Rotate the locking differential coil assembly wiring harness towards the top of the axle housing in order to align the locking differential coil assembly lock tab with the top of the differential bearing cap.
  15. Fig 4: Locking Differential Coil Assembly Wiring From Axle Housing
    GM841717Courtesy of GENERAL MOTORS CORP.
  16. Install the locking differential coil assembly wiring through the axle housing opening.

    Push the wiring grommet through the axle housing opening until fully seated.

  17. Fig 5: Left Side Differential Bearing Cap Bolts
    GM841749Courtesy of GENERAL MOTORS CORP.
  18. Install the left side differential bearing cap.

    Route the locking differential coil assembly wires around the differential bearing cap.

  19. Install the left side differential bearing cap bolts.
  20. NOTE: Refer to Fastener Notice .
  21. Tighten the bearing cap bolts.

    Tighten:  Tighten the bearing cap bolts to 85 N.m (63 lb ft).

  22. Install the locking differential coil assembly lock.
  23. Fig 6: Locking Differential Coil Assembly Lock Bolt
    GM841754Courtesy of GENERAL MOTORS CORP.
  24. Install the new locking differential coil assembly lock bolt.

    Tighten:  Tighten the locking differential coil assembly lock bolt to 26 N.m (19 lb ft).

  25. Fig 7: Differential Bearing Adjuster Nut Lock
    GM667492Courtesy of GENERAL MOTORS CORP.
  26. Install the right side differential bearing adjuster nut lock.
  27. Install the differential bearing adjuster nut lock bolt.

    Tighten:  Tighten the differential bearing adjuster nut lock bolt to 26 N.m (19 lb ft).

  28. Fig 8: Electronic Locking Differential Coil Connector Housing
    GM841758Courtesy of GENERAL MOTORS CORP.
  29. Install the locking differential coil assembly wires to the locking differential coil connector.
  30. Fig 9: Positive Terminal Lock Reinforcer
    GM841763Courtesy of GENERAL MOTORS CORP.
  31. Install the positive terminal lock reinforcer.
  32. Connect the locking differential coil connector to the wire harness.
  33. Install the axle shafts. Refer to Rear Axle Shaft Replacement .
  34. Install the rear axle housing cover and a new gasket. Refer to Rear Axle Housing Cover and Gasket Replacement .
  35. Install the brake calipers. Refer to Rear Brake Caliper Replacement .
  36. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
  37. Fill the axle with lubricant. Use the proper fluid. Refer to Rear Axle Lubricant Replacement .
  38. Lower the vehicle.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.