GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN 46112 Tensioner Retraction Pins
    • EN 48383 Camshaft Retaining Tools
    • EN 48589 Crankshaft Rotation Socket
    • EN 45027 Reset Tool

For equivalent regional tools, refer to Special Tools.


    Object Number: 1306381  Size: SH
  1. Ensure that the primary timing chain tensioner (3) is being installed.

  2. Object Number: 1306417  Size: SH
  3. Using the EN 45027 reset tool , reset the primary timing chain tensioner plunger.

  4. Object Number: 1306418  Size: SH
  5. Install the plunger into the primary timing chain tensioner body.

  6. Object Number: 1306420  Size: SH
  7. Compress the plunger into the body and lock the primary timing chain tensioner by inserting the EN 46112 pins into the access hole in the side of the primary timing chain tensioner body.
  8. Slowly release pressure on the primary timing chain tensioner. The primary timing chain tensioner should remain compressed.

  9. Object Number: 2026595  Size: SH
  10. Ensure the primary timing chain tensioner mounting surface on the engine block have not any burrs or defects that would degrade the sealing of the NEW primary timing chain tensioner gasket.
  11. Install the NEW primary timing chain tensioner gasket (2).
  12. Install the primary timing chain tensioner (1).
  13. Caution: Refer to Fastener Caution in the Preface section.

  14. Install primary timing chain tensioner bolts (3) and tighten in 2 passes:
  15. 9.1. Tighten the primary timing chain tensioner bolts to  5 N·m(44  lb in) on the first pass.
    9.2. Tighten the primary timing chain tensioner bolts to  23 N·m(17 lb ft) on the second pass.

    Object Number: 1853233  Size: SH
  16. Release the placement of the primary timing by pulling out the EN 46112 pin and unlocking the tensioner plunger.

  17. Object Number: 1853237  Size: SH
  18. Verify the primary timing chain and secondary timing chain bank 2 timing mark alignments (1-12). Refer to Camshaft Timing Drive Chain Alignment Diagram.

  19. Object Number: 1306426  Size: SH
  20. Remove the EN 48383-1 retainer from the rear of the camshafts bank 2.

  21. Object Number: 1866953  Size: SH
  22. Using the EN 48589 socket , rotate the crankshaft and crankshaft sprocket from the stage 1 alignment position (1) to the stage 2 alignment position (2)  115  degrees in order to install the secondary timing chain bank 1 components.

  23. Object Number: 1306428  Size: SH
  24. Install the EN 48383-2 retainer onto the rear of the camshafts bank 2.

  25. Object Number: 946124  Size: SH
  26. Install the EN 48383-3 retainer onto the rear of the camshafts bank 1.