GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Astro - 4WD 🢒 Engine 🢒 Engine Electrical 🢒 Transfer Case Assembly Replacement

Removal Procedure

    Object Number: 648043 Size: SH
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General information.
  2. Remove the engine brace mounting bolts.
  3. Remove the engine brace.
  4. Remove the transfer case shield. Refer to Transfer Case Shield Replacement .
  5. Remove the rear propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
  6. Remove the front propeller shaft. Refer to Front Propeller Shaft Replacement in Propeller Shaft.

    7. Object Number: 648014 Size: SH
  7. Remove the motor/encoder electrical connector.

    8. Object Number: 647994 Size: SH
  8. Remove the transfer case electrical wiring harness.

    9. Object Number: 715667 Size: SH
  9. Remove the transfer case vent hose.

    10. Important: To perform the following service procedure, the transmission mount must be removed to gain access to the bottom retaining nut of the transfer case. Do not support the transmission by the oil pan.

  10. Support the transmission with a suitable transmission jack.

    11. Object Number: 647997 Size: SH
  11. Remove the transmission mount retaining nuts.

    12. Object Number: 647998 Size: SH

    Important: Raise the transmission assembly enough to clear the rear crossmember.

  12. Remove the transmission mount bolts.

    13. Object Number: 648001 Size: SH
  13. Remove the transmission mount assembly.

    14. Object Number: 648003 Size: SH
  14. Remove the transfer case bottom retaining nut.

    15. Important: The transmission mount must be replaced in it's original position to support the transmission. When reinstalling the transmission mount, it is not necessary reinstall the mounting nuts and bolts. The weight of the transmission and engine will hold the transmission mount in place until this service procedure is completed.

  15. Install the transmission mount.
  16. Remove the transmission jack stand from the transmission.

    17. Object Number: 648011 Size: SH
  17. Remove the transfer case upper retaining nuts.

    18. Object Number: 648037 Size: SH
  18. Install the transmission jack to the transfer case.
  19. Remove the transfer case assembly.

    20. Object Number: 654219 Size: SH

    Important: DO NOT reuse the old gasket if it is damaged. DO NOT use any type of sealer in place of the gasket.

  20. Remove the transfer case gasket.

Installation Procedure

    Object Number: 654219 Size: SH

    Important: Make sure that the locating tab on the gasket is in the proper location. The locator tab should be facing up.

  1. Install a new transfer case gasket.

    2. Object Number: 648037 Size: SH
  2. Install the transfer case assembly.

    3. Object Number: 648011 Size: SH

    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.

  3. Install the transfer case retaining nuts.

    4. Tighten
    Tighten the transfer case retaining nuts to 55 N·m (40 lb ft).

  4. Remove the transmission jack from the transfer case.
  5. Install the transmission jack to the transmission.

    6. Object Number: 648001 Size: SH
  6. Install the transmission mount.

    7. Object Number: 647998 Size: SH
  7. Install the transmission mount bolts.

    8. Tighten
    Tighten the transmission mount bolts 47 N·m (35 lb ft).

  8. Lower the transmission into place.
  9. Remove the transmission jack stand.

    10. Object Number: 647997 Size: SH
  10. Install the transmission mount retaining nuts.

    11. Tighten
    Tighten the transmission mount retaining nuts to 40 N·m (29 lb ft).


    Object Number: 648014 Size: SH
  11. Install the motor/encoder electrical connector.

    12. Object Number: 647994 Size: SH
  12. Install the transfer case electrical wiring harness.

    13. Object Number: 715667 Size: SH
  13. Install the transfer case vent hose.
  14. Install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
  15. Install the front propeller shaft. Refer to Front Propeller Shaft Replacement in Propeller Shaft.

    16. Object Number: 648043 Size: SH
  16. Install the engine brace.
  17. Install the engine brace mounting bolts.

    18. Tighten
    Tighten the engine brace mounting bolts to 50 N·m (37 lb ft).

  18. Inspect the transfer case fluid level. Refer to Transfer Case Fluid Replacement .
  19. Install the transfer case shield. Refer to Transfer Case Shield Replacement .
  20. Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.