GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39946 Crankshaft Socket

Removal Procedure


    Object Number: 1674296  Size: SH
  1. Remove the oil pump. Refer to Oil Pump Replacement .
  2. Remove the crankshaft sprocket to oil pump drive friction washer.

  3. Object Number: 517185  Size: SH
  4. Align the primary timing marks (1) using the J 39946 .
  5. Remove the secondary camshaft drive chains. Refer to Secondary Camshaft Drive Chain Replacement - Left Side and Secondary Camshaft Drive Chain Replacement - Right Side .
  6. Remove the primary drive chain tensioner. Refer to Primary Camshaft Drive Chain Tensioner Replacement .

  7. Object Number: 928361  Size: SH
  8. Remove the oil outlet tube (4). Refer to Oil Pump Outlet Tube Removal .

  9. Object Number: 928395  Size: SH
  10. Remove the primary camshaft drive chain guide bolts and guide.

  11. Object Number: 928389  Size: SH
  12. Remove the camshaft intermediate sprocket retaining bolt.

  13. Object Number: 928397  Size: SH
  14. Remove the following as an assembly:
  15. • The primary camshaft drive chain (3)
    • The crankshaft sprocket
    • The camshaft intermediate sprocket

    Object Number: 1674295  Size: SH
  16. Remove the crankshaft to crankshaft sprocket friction washer.
  17. Clean and inspect the camshaft timing drive components. Refer to Camshaft Timing Drive Components Cleaning and Inspection .

Installation Procedure


    Object Number: 1674306  Size: SH

    Important: Ensure the proper friction washer is installed in the correct position.

  1. Select the crankshaft to crankshaft sprocket friction washer (1). The outer diameter is 63.5 mm (2.5000 in), an inner diameter of 45.25 mm (1.7815 in) and a notch to clear the crankshaft pin.

  2. Object Number: 1674295  Size: SH
  3. Install the crankshaft to crankshaft sprocket friction washer.

  4. Object Number: 207540  Size: SH
  5. Align the timing marks (1) of the camshaft intermediate and crankshaft sprockets. The marks should be aligned vertically in the installed position.
  6. Install the primary camshaft drive chain on the drive sprockets.

  7. Object Number: 928397  Size: SH
  8. Ensure the number one piston is at Top Dead Center (TDC) and the crankshaft pin is approximately at the 1 o'clock position. Use the J 39946 to rotate the crankshaft as necessary.
  9. Install the following as an assembly:
  10. • The primary camshaft drive chain (3)
    • The crankshaft sprocket
    • The camshaft intermediate sprocket

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 928389  Size: SH
  11. Install the camshaft intermediate sprocket retaining bolt.
  12. Tighten
    Tighten the camshaft intermediate sprocket retaining bolt to 60 N·m (44 lb ft).


    Object Number: 928395  Size: SH
  13. Install the primary drive chain guide.
  14. Install the primary drive chain guide bolts.
  15. Tighten
    Tighten the primary drive chain guide bolts to 25 N·m (18 lb ft).

  16. Install the primary drive chain tensioner. Refer to Primary Camshaft Drive Chain Tensioner Replacement .

  17. Object Number: 928361  Size: SH
  18. Install the oil outlet tube (4) and bolts. Refer to Oil Pump Outlet Tube Installation .
  19. Tighten
    Tighten the oil outlet tube bolts to 10 N·m (89 lb in).

  20. Install the secondary camshaft drive chains. Refer to Secondary Camshaft Drive Chain Replacement - Left Side and Secondary Camshaft Drive Chain Replacement - Right Side .
  21. Remove the pin from the primary timing chain tensioner release lever.

  22. Object Number: 517185  Size: SH
  23. Ensure the primary timing marks (1) are aligned vertically.

  24. Object Number: 1674296  Size: SH
  25. Install the crankshaft sprocket to oil pump drive friction washer. The crankshaft sprocket to oil pump drive friction washer outer diameter is 62.0 mm (2.4410 mm) and the inner diameter is 45.25 mm (1.7815 in).
  26. Install the oil pump. Refer to Oil Pump Replacement .