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Home >> Buick >> 2021 >> Envision Avenir, AWD >> Repair and Diagnosis >> Transmission >> Power Transfer Unit/Transfer Case - AAM >> Repair Instructions - Off Vehicle >> Power Transfer Unit Case Assemble >> Power Transfer Unit Case Assemble
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Power Transfer Unit Case Assemble

  1. GM3793540Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Idler Gear Shaft Access Tube O-ring (1) - Install NEW

    2. NOTE:

    The tube orientation for assembly. Install the tube with the knurled OD area facing the extension housing.

  2. Power Transfer Unit Idler Shaft Tube (2) - Install
    3. NOTE:

    Make sure the seal bore is clean and free of oil or dirt.

    NOTE:

    Install the seal into the bore until the tool bottoms against the case half.

  3. Install the NEW rear power transfer unit input shaft seal (4) with the notched surface of the seal facing the DT-51466  Seal Installer (3) and the metal ID portion of the seal facing the DT-51466  Seal Installer (3).
  4. GM3793537Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Make sure the seal bore is clean and free of oil or dirt.

    NOTE:

    Install the seal into the bore until the tool bottoms against the case half.

    Install the NEW front power transfer unit input shaft seal (1) with the notched surface of the seal facing the DT-51466  Seal Installer (2) and the metal ID portion of the seal facing the DT-51466  Seal Installer (2).

  5. Power Transfer Unit Idler Gear Shaft Tube O-ring (4) - Install NEW
    6. NOTE:

    Install the locating pins as required.

  6. Power Transfer Unit Locating Pin (3) - Install [2x]
  7. GM5830650Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Face Seal (1) - Install NEW

  8. GM3793533Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Idler Shaft (1) - Install

  9. Power Transfer Unit Input Shaft (2) - Install
  10. Fig 1: Exploded View Of Power Transfer Unit Cover Housing Components And Bolts With Tightening Sequence
    GM3793523Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Inspect the extension housing and main housing seal surfaces to ensure they are clean and free of damage prior to assembly.

    Power Transfer Unit Cover Housing Seal (1) - Install NEW

  11. Power Transfer Unit Cover Housing (2) - Install
    12. CAUTION:

    Refer to Fastener Caution .

    CAUTION:

    This vehicle is equipped with torque-to-yield or single use fasteners. Install a NEW torque-to-yield or single use fastener when installing this component. Failure to replace the torque-to-yield or single use fastener could cause damage to the vehicle or component.

  12. If NEW threaded components are being installed, loosen the adhesive using a metal pick or similar tool before proceeding. If threaded components are reused, prepare the threaded components using the following steps:
  13. Remove any loose cured adhesive from the external threads of the components using a lint free cloth.
  14. Thread the cleaned components into the internal mating threads and remove to loosen trapped cured adhesive.
  15. Remove loose debris from internal and external threads using compressed air.
  16. Apply liquid thread locking adhesive in a strip along half of the length of the external threads, starting at the tip, just prior to installation. Adhesives, Fluids, Lubricants, and Sealers 
  17. Power Transfer Unit Cover Housing Bolt (3) - Install NEW and tighten in sequence [10x] 28 N.m (21 lb ft)
  18. GM5666985Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Shift Actuator Seal (3) - Install NEW

  19. Power Transfer Unit Shift Actuator (2) - Install
  20. Power Transfer Unit Shift Actuator Bolt (1) - Install and tighten [4x] 9 N.m (80 lb in)
  21. GM3793514Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Make sure the seal bore is clean and free of oil or dirt.

    Using the DT-51467  Seal Installer and DT-305-1  Driver Handle (4), install a NEW power transfer unit output shaft seal (1).

  22. Power Transfer Unit Propeller Shaft Seal (2) - Install NEW
    23. NOTE:

    When installing a NEW half shaft retaining clip, open the clip only as far as necessary to fit the clip over the shaft. Opening the clip too far will damage it.

    NOTE:

    Start one end of the clip in the shaft groove and slowly push the clip onto and over the shaft.

  23. Power Transfer Unit Propeller Shaft Retainer (3) - Install NEW
  24. GM5667429Courtesy of GENERAL MOTORS COMPANY
    CAUTION:

    Do not nick, scratch or damage the sealing surface. The sealing surface is a machined surface. Damage to the machined surface can cause leakage.

    Power Transfer Unit Intermediate Drive Shaft Bearing Retaining Ring (1) - Install

    25. NOTE:

    Use a press to install the bearing to the shaft.

  25. Power Transfer Unit Intermediate Drive Shaft Bearing (2) - Install
    26. CAUTION:

    Do not nick, scratch or damage the sealing surface. The sealing surface is a machined surface. Damage to the machined surface can cause leakage.

  26. Power Transfer Unit Intermediate Drive Shaft Bearing Retaining Ring (1) - Install
  27. Power Transfer Unit Intermediate Drive Shaft (3) - Install
  28. Power Transfer Unit Intermediate Drive Shaft Retainer (4) - Install
  29. GM3793508Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Lubricate the OD area of the seal with a light film of grease or oil prior to installation.

    Using the DT-51466  Seal Installer and DT-305-1  Driver Handle (2) install a NEW power transfer unit intermediate drive shaft to input shaft seal (1).

  30. Power Transfer Unit Half Shaft Seal (4) - Install NEW
    31. CAUTION:

    When installing a new bearing retaining ring, open the ring only as far as necessary to fit the ring over the shaft. Opening the ring too far will damage it.

  31. Power Transfer Unit Half Shaft Retainer Clip (3) - Install NEW
  32. GM5666056Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The plug and seal are only available as an assembly. Install a NEW plug with seal during assembly.

    Power Transfer Unit Drain Plug (2) - Install NEW and tighten to 40 N.m (30 lb ft)

    33. NOTE:

    The plug and seal are only available as an assembly. Install a NEW plug with seal during assembly.

    NOTE:

    Tighten the oil fill plug only after the assembly has been filled with fluid. Adhesives, Fluids, Lubricants, and Sealers 

  33. Power Transfer Unit Fill Plug (1) - Install NEW and tighten to 40 N.m (30 lb ft)
    34. NOTE:

    Apply sealant to the threads of the connector. Adhesives, Fluids, Lubricants, and Sealers 

  34. Power Transfer Unit Vent Hose Connector (3) - Install NEW and tighten to 20 N.m (15 lb ft)
  35. GM5666686Courtesy of GENERAL MOTORS COMPANY

    Remove the power transfer unit case (3) and the DT-36842  Transaxle Holding Fixture (2) from the DT-3289-20  Holding Fixture (1).

  36. Remove the DT-36842  Transaxle Holding Fixture (2) from the power transfer unit case (3).
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