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Home >> Buick >> 2020 >> Envision Essence, AWD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> 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 - Rear (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 Gear Shaft Access 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 seal with the notched surface of the power transfer unit rear input shaft seal (4) facing the DT-51466  Seal Installer (3) with the metal ID portion of the seal facing the DT-51466  Seal Installer (3).
  4. GM3793537Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Face Seal - Install NEW

    5. 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.

  5. Install the NEW seal with the notched surface of the power transfer unit front input shaft seal (1) facing the DT-51466  Seal Installer (2) with the metal ID portion of the seal facing the DT-51466  Seal Installer (2).
  6. Power Transfer Unit Idler Gear Shaft Access Tube O-ring - Front (4) - Install NEW
    7. NOTE:

    Install the locating pins as required.

  7. Power Transfer Unit Locating Pin [2x] (3) - Install
  8. GM5620628Courtesy of GENERAL MOTORS COMPANY

    Install the power transfer unit face seal (1).

    9. NOTE:

    Use a press to install the sleeve. Install the sleeve with the tapered end facing away from case. Press the sleeve into the housing until it bottoms in the case half bore.

  9. Install the NEW power transfer unit alignment sleeve (2).
  10. GM3793533Courtesy of GENERAL MOTORS COMPANY

    Power Transfer Unit Idler Shaft (1) - Install

  11. Power Transfer Unit Input Shaft (2) - Install
  12. Fig 1: Exploded View Of Power Transfer Unit Extension Housing Components 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

  13. Power Transfer Unit Extension Housing (2) - Install
    14. 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.

    NOTE:

    Clean the internal threads (no residual pre-applied adhesive allowed).

    NOTE:

    Apply threadlocker to the threads of the NEW bolts. Adhesives, Fluids, Lubricants, and Sealers 

  14. Power Transfer Unit Extension Housing Bolt (3) - Install NEW [10x]
  15. 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, install a NEW power transfer unit output shaft seal (1).

  16. Power Transfer Unit Propeller Shaft Seal (2) - Install NEW
    17. 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.

  17. Power Transfer Unit Propeller Shaft Retainer (3) - Install NEW
  18. GM3793517Courtesy 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 NEW

    19. NOTE:

    Use a press to install the bearing to the shaft.

  19. Power Transfer Unit Intermediate Drive Shaft Bearing (2) - Install
    20. 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.

  20. Power Transfer Unit Intermediate Drive Shaft Bearing Retaining Ring (3) - Install NEW
  21. Power Transfer Unit Intermediate Drive Shaft (4) - Install
  22. Power Transfer Unit Intermediate Drive Shaft Retainer (5) - Install
  23. 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 to install a NEW power transfer unit cover-to-intermediate drive shaft seal (1).

  24. Power Transfer Unit Half Shaft Seal (2) - Install NEW
    25. 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.

  25. Power Transfer Unit Half Shaft Retainer Clip (3) - Install NEW
  26. Fig 2: Identifying Power Transfer Unit Oil Fill Plug, Oil Drain Plug And Vent Hose Connector Components
    GM3793510Courtesy 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 (1) - Install NEW

    27. 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 

  27. Power Transfer Unit Fill Plug (2) - Install NEW
    28. NOTE:

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

  28. Power Transfer Unit Vent Hose Connector (3) - Install NEW
  29. GM3793505Courtesy 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).

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