Document ID# 727015
2001 GMC Truck GMC K Sierra - 4WD
2GTEK69U711xxxxxx
 

Transfer Case Assemble

Assembly Procedure

Important

The transfer case housings are magnesium. All steel external components must be isolated from contacting the magnesium or galvanic corrosion will occur. If the fill and drain plugs are to be replaced, they must be made aluminum. All fasteners should be nylon coated and have aluminum washers under the bolt heads. Seals must have rubber on their outside diameters. Brackets used under the case bolts must be aluminum.

Important

After installing any of the retaining rings in the following service procedures, always make sure that the retaining rings are properly seated before proceeding to the next service procedure. If the retaining ring will not seat properly or is damaged, replace the retaining ring.


    Object Number: 165657  Size: SH
    Click here for detailed picture of above image.
  1. Install the mounting studs to 1.16 inch to 1.20 inch in height (if removed).
    Object Number: 735644  Size: SH
    Click here for detailed picture of above image.

    Important

    When installing the input gear bearing, make sure the printing on the bearing is facing up (toward the technician installing the bearing).

  2. Using a press, install the input gear bearing.
    Object Number: 729520  Size: SH
    Click here for detailed picture of above image.
  3. Install the input gear bearing retaining ring.
    Object Number: 729518  Size: SH
    Click here for detailed picture of above image.
  4. Install the input gear
    Object Number: 729426  Size: SH
    Click here for detailed picture of above image.
  5. Install the input gear retaining ring.
    Object Number: 735644  Size: SH
    Click here for detailed picture of above image.

    Important

    When installing the front output shaft bearing, make sure the printing on the bearing is facing up (toward the technician installing the bearing).

  6. Using a press, install the front output shaft bearing.
    Object Number: 729525  Size: SH
    Click here for detailed picture of above image.
  7. Using a press, install the front output shaft.
    Object Number: 717108  Size: SH
    Click here for detailed picture of above image.
  8. Install the front output shaft retaining ring.
    Object Number: 729424  Size: SH
    Click here for detailed picture of above image.
  9. Install the viscous coupling.
    Object Number: 729528  Size: SH
    Click here for detailed picture of above image.
  10. Install the mainshaft assembly.
    Object Number: 729532  Size: SH
    Click here for detailed picture of above image.

    Important

    The blue colored link must be facing up (toward the rear of the vehicle).

  11. Install the drive chain and sprockets.
    Object Number: 729562  Size: SH
    Click here for detailed picture of above image.
  12. Install the driven sprocket retaining ring.
    Object Number: 729534  Size: SH
    Click here for detailed picture of above image.
  13. Install the carrier retaining ring.
    Object Number: 729533  Size: SH
    Click here for detailed picture of above image.

    Important

    Make sure that the spline engages with both the sprocket and viscous coupling cover. The sun gear shoulder will bottom on the sprocket if installed correctly.

  14. Install the sun gear.
    Object Number: 729418  Size: SH
    Click here for detailed picture of above image.
  15. Install the sun gear thrust washer.
    Object Number: 729555  Size: SH
    Click here for detailed picture of above image.

    Important

    When installing the carrier assembly, a snap should be felt and heard when the carrier is properly seated.

  16. Install the carrier assembly.
    Object Number: 729556  Size: SH
    Click here for detailed picture of above image.
  17. Install the rear output shaft in the annulus gear.
    Object Number: 729557  Size: SH
    Click here for detailed picture of above image.
  18. Install the annulus gear retaining ring. If the retaining ring is not fully seated and the annulus gear becomes disengaged from the rear output shaft during operation, vehicle could roll when put in park. Also, damage to the viscous coupling could occur.
    Object Number: 729402  Size: SH
    Click here for detailed picture of above image.
  19. Install the oil pump assembly.
    Object Number: 729400  Size: SH
    Click here for detailed picture of above image.
  20. Install the tone wheel retaining ring.
    Object Number: 730254  Size: SH
    Click here for detailed picture of above image.

    Important

    The tone wheel should bottom on the retaining ring.

  21. Using a press, install the tone wheel.
    Object Number: 729559  Size: SH
    Click here for detailed picture of above image.

    Important

    Ensure that the retaining ring groove on the rear output shaft bearing is facing up (toward the rear of the vehicle).

  22. Using a press, install the rear output shaft bearing.
    Object Number: 729561  Size: SH
    Click here for detailed picture of above image.
  23. Install the rear output shaft bearing retaining ring.
    Object Number: 729398  Size: SH
    Click here for detailed picture of above image.
  24. Install the rear output shaft assembly.
    Object Number: 724251  Size: SH
    Click here for detailed picture of above image.
  25. Install the wear clip in the rear case half.
    Object Number: 729396  Size: SH
    Click here for detailed picture of above image.

    Important

    Ensure that the O-ring is in place in the oil pump.

  26. Install the oil pump screen and magnet assembly.

    Important

    Ensure that both sealing surfaces on the front and rear case halves are free of any silicone sealant, dirt or cleaning solvent.

  27. Apply an 1/8 in bead of RTV sealant GM P/N 12345739 or equivalent to the front case half. Excessive RTV will squeeze into the case and plug the oil pump pick up screen.
  28. Align the rear case on the rear output shaft bearing.
    Object Number: 649760  Size: SH
    Click here for detailed picture of above image.
  29. Insert a pair of snap ring pliers in the slot.
  30. Open the outer rear output shaft bearing retaining ring.

    Important

    Ensure that the rear output shaft bearing retaining ring is seated in the groove properly by prying up on the shaft on the rear output shaft assembly.

  31. Lower the rear case on to the rear output shaft bearing.
  32. Remove the snap ring pliers.

    Important

    Ensure that when the rear case is installed, that it is squarely seated on the alignment dowels.

  33. Lower the rear case on to the alignment dowels
    Object Number: 740281  Size: SH
    Click here for detailed picture of above image.

    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.

    Important

    Ensure that the retaining bracket under the bolt is in line with the speed sensor.

  34. Install the transfer case bolts. Tighten

    Tighten the retaining bolts to 31 Nm (23 lb ft)


    Object Number: 678288  Size: SH
    Click here for detailed picture of above image.
  35. Using the J 42738 , install the input gear seal.
    Object Number: 687288  Size: SH
    Click here for detailed picture of above image.

    Important

    Ensure that the drain hole on the boot of the rear output shaft seal is facing down toward the ground.

  36. Using the J 37668-A , install the rear output shaft seal.
    Object Number: 678236  Size: SH
    Click here for detailed picture of above image.
  37. Using the J 43484 (2) and the J 8092 (1) install the front output shaft seal.
    Object Number: 662047  Size: SH
    Click here for detailed picture of above image.
  38. Install the transfer case speed sensor. Tighten

    Tighten the transfer case speed sensor to 15 Nm (11 lb ft).


    Object Number: 660281  Size: SH
    Click here for detailed picture of above image.

    Important

    Use only drain and fill plugs that are made from aluminum. Steel or brass plugs are not compatible with the magnesium case.

  39. Install the drain plug. Tighten

    Tighten the drain plug to 20 Nm (15 lb ft).


    Object Number: 660282  Size: SH
    Click here for detailed picture of above image.
  40. Install the fill plug. Tighten

    Tighten the fill plug to 20 Nm (15 lb ft).


    Object Number: 724554  Size: SH
    Click here for detailed picture of above image.
  41. Install the rubber plug.

  Document ID# 727015
2001 GMC Truck GMC K Sierra - 4WD
2GTEK69U711xxxxxx