GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 42069 Timing Belt Alignment Kit
    • J 42098 Crank Hub TORX® Socket

Installation and Initial Adjustment Procedure


    Object Number: 345381  Size: SH

    Notice: When installing a new or used timing belt, the directional arrows on the timing belt must be matched with the rotation of the crankshaft. If this precaution is not observed, excessive wear and timing belt failure may occur.

    Important: Guide marks are printed on the timing belt to aid in installation. If these marks are not identifiable, install a new belt.

    Arrows are printed on the timing belt indicating the required direction of travel. When installing the timing belt, ensure the arrows are traveling in engine rotational direction, clockwise.

    Do not crimp or bind the timing belt when handling or installing.

  1. Install the J 42069-1 and J 42069-2 to hold camshafts.

  2. Object Number: 826215  Size: SH
  3. Slip the timing belt though the 3 and 4 camshaft simultaneously, ensuring the dash marks on the timing belt align with the marks on the camshaft gears and the notches on the rear timing belt cover.
  4. Route the timing belt through the upper idler pulley.
  5. Slip the timing belt though the 1 and 2 camshaft gears simultaneously, ensuring the dash marks on the timing belt align with the marks on the camshaft gears and the notches on the rear timing belt cover.
  6. Route the timing belt through the timing belt tensioner.

  7. Object Number: 826214  Size: SH
  8. Ensure the crankshaft is at TDC.
  9. Install the timing belt on the crankshaft drive gear with the double dash mark on the belt aligned with the marks on the oil pump and on the belt drive gear.

  10. Object Number: 826218  Size: SH
  11. Using the J 42098 rotate the crankshaft to 3° before TDC making sure the timing belt does not jump teeth.
  12. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 826217  Size: SH
  13. Install the lower idler pulley with the timing belt on it.
  14. Install the lower idler pulley bolt.
  15. Tighten
    Tighten the lower idler pulley bolt to 40 N·m (30 lb ft).


    Object Number: 826214  Size: SH
  16. Turn the crankshaft back to TDC, using the J 42098 .

  17. Object Number: 345823  Size: MH
  18. Apply tension to the timing belt, at the upper idler pulley by turning the high point of the eccentric to approximately the 9 o'clock position. Tighten the idler pulley locking bolt, while holding the eccentric with the J 42069-40, until snug.

  19. Object Number: 833453  Size: MH
  20. Rotate the tensioner eccentric counter clockwise to full stop, turn the eccentric back until the reference mark is (a) 1 mm (0.039 in) over the flange.
  21. Tighten the timing belt tensioner until snug, the locking nut will be tightened to specifications after all final adjustments are made.

  22. Object Number: 826215  Size: SH
  23. Inspect the alignment marks on the timing belt to ensure that they are aligned with the appropriate reference points on the camshaft gears, the rear timing belt cover and on the oil pump housing.

  24. Object Number: 345367  Size: SH
  25. Rotate the crankshaft, with the J 42098 , in the clockwise direction 2 revolutions stopping at 60 degrees BTDC.

  26. Object Number: 345381  Size: SH
  27. Remove the J 42069-1 and J 42069-2.

  28. Object Number: 345377  Size: SH
  29. Install the J 42069-10 to the crankshaft drive gear.
  30. Turn the crankshaft until the lever of the J 42069-10 firmly contacts the water pump flange.
  31. Secure the moveable lever of the tool to the water pump pulley flange.

  32. Object Number: 159005  Size: SH

    Important: The alignment marks on the timing belt will no longer align with the marks on the camshaft gears after one or more engine revolutions.

  33. Inspect the alignment of the reference marks on the camshaft gears with the notches on the rear timing belt cover.

  34. Object Number: 826214  Size: SH
  35. Inspect the alignment of the reference mark on the crankshaft drive gear and oil pump housing.

  36. Object Number: 826220  Size: SH

    Important: The reference marks on both sets of the camshaft gears must match exactly with the marks on the J 42069-20 checking gage.

  37. Use the J 42069-20 to inspect the alignment of the camshaft gears 3 and 4.
  38. Use the J 42069-20 to inspect the alignment of the camshaft gears 1 and 2.

  39. Object Number: 826216  Size: SH
  40. If timing belt adjustment IS REQUIRED, refer to Timing Belt Timing Procedure.
  41. If timing belt adjustment IS NOT REQUIRED, set the final timing belt tension:
  42. 26.1. Loosen the timing belt eccentric locking nut.
    26.2. Turn the eccentric counter clockwise to full stop, then back until the reference mark is (a) 3-4 mm (0.118-0.158 in) above the mark on the flange.

    Tighten
    Tighten the timing belt tensioner eccentric locking nut to 20 N·m (15 lb ft).


    Object Number: 345823  Size: MH
  43. Hold the upper idler pulley eccentrics in place with the J 42069-40.
  44. Tighten
    Tighten the upper idler pulley bolt to 40 N·m (30 lb ft).


    Object Number: 345377  Size: SH
  45. Remove the J 42069-10 from the engine.

  46. Object Number: 345367  Size: SH
  47. For final inspection rotate the engine in the clockwise direction two revolutions until reaching 60 degrees BTDC.

  48. Object Number: 345377  Size: SH
  49. Install the J 42069-10 to the crankshaft drive gear.

  50. Object Number: 345377  Size: SH
  51. Turn the crankshaft until the lever of the J 42069-10 firmly contacts the water pump flange.
  52. Secure the moveable lever of the tool to the water pump pulley flange.

  53. Object Number: 159005  Size: SH

    Important: The alignment marks on the timing belt will no longer align with the marks on the camshaft gears after one or more engine revolutions.

  54. Inspect the alignment of the reference marks on the camshaft gears with the notches on the rear timing belt cover.

  55. Object Number: 831318  Size: SH
  56. Inspect the alignment of the reference mark on the crankshaft drive gear and oil pump housing.

  57. Object Number: 826220  Size: SH
  58. Use the J 42069-20 to inspect the alignment of the camshaft gears 3 and 4.
  59. Use the J 42069-20 to inspect the alignment of the camshaft gears 1 and 2.
  60. If the reference marks on the camshaft gears do not match exactly, timing belt adjustment IS REQUIRED.
  61. Refer to the Timing Belt Timing Procedure.

  62. If the reference marks match exactly, further timing belt adjustment IS NOT necessary.
  63. Continue with reassembly of the engine.

  64. Ensure all of the tools are removed from the engine.

Timing Belt Timing Procedure


    Object Number: 345823  Size: MH

    Important: The following steps are the continuation of installing the timing belt and must not be performed as a stand-alone operation.

    It is not uncommon to repeat steps and make several engine revolutions to achieve the proper level of timing belt adjustment.

  1. Apply the J 42069-20 checking gage to camshaft gears 1 and 2.
  2. Inspect the relationship of the marks on the camshaft gears to the marks on the J 42069-20 checking gage. They must match exactly, if not, timing belt adjustment is required.
  3. Continue to the next applicable procedure.

Marks on Camshaft Gears 1 and 2 Align to the LEFT of J 42069-20

  1. Loosen the timing belt idler pulley for camshaft gears 1 and 2.

  2. Object Number: 345823  Size: MH
  3. Use the J 42069-40 adjustment wrench to turn eccentric on the idler pulley COUNTERCLOCKWISE until the marks on the camshaft gears and on the J 42069-20 checking gage are in alignment, the high point of the idler pulley eccentric will be in approximately the 9 o'clock position.
  4. Tighten
    Tighten the timing belt idler pulley bolt, while holding the eccentric in place with the J 42069-40 adjustment wrench to prevent movement, to 40 N·m (30 lb ft).

  5. Remove the J 42069-10 crankshaft locking tool and the J 42069-20 checking gage.
  6. Turn the crankshaft in the engine rotational direction 2 revolutions with the J 42098 . Stop at 60 degrees BTDC.
  7. Install the J 42069-10 crankshaft locking tool to the crankshaft drive gear with the knurled bolt.
  8. Use the J 42098 to carefully turn the crankshaft until the lever of the J 42069-10 firmly contacts the water pump pulley flange.
  9. Secure the moveable lever of the tool to the water pump pulley flange.
  10. Install the J 42069-20 checking gage to camshaft gears 1 & 2.
  11. Inspect the alignment of the marks on the camshaft gears in reference to the marks on the J 42069-20 checking gage.
  12. Repeat the procedure again if the marks do not align.
  13. If camshaft gears 1 and 2 are properly aligned, set the final timing belt tensioner as outlined in Timing Belt Tensioner Adjustment at the end of this procedure.

Marks on Camshaft Gears 1 and 2 Align to the RIGHT of J 42069-20

  1. Loosen the timing belt idler pulley for camshaft gears 1 and 2.

  2. Object Number: 345830  Size: MH
  3. Slacken the timing belt by turning the eccentric on the idler pulley CLOCKWISE with the J 42069-40 adjustment wrench until the marks on the camshaft gears and the marks on the J 42069-20 checking gage are in alignment, the high point of the idler pulley eccentric will be in approximately the 9 o'clock position.
  4. Tighten
    Tighten the timing belt idler pulley bolt, while holding the eccentric in place with the J 42069-40 adjustment wrench to prevent movement, to 40 N·m (30 lb ft).

  5. Remove the J 42069-10 crankshaft locking tool and the J 42069-20 checking gage.
  6. Turn the crankshaft in the engine rotational direction 2 revolutions with the J 42098 . Stop at 60 degrees BTDC.
  7. Install the J 42069-10 crankshaft locking tool to the crankshaft drive gear with the knurled bolt.
  8. Use the J 42098 to carefully turn the crankshaft until the lever of the J 42069-10 firmly contacts the water pump pulley flange.
  9. Secure the moveable lever of the tool to the water pump pulley flange.
  10. Install the J 42069-20 checking gage to camshaft gears 1 and 2.
  11. Inspect the alignment of the marks on the camshaft gears in reference to the marks on the J 42069-20 checking gage.
  12. Repeat the procedure again if the marks do not align.
  13. If camshaft gears 1 and 2 are properly aligned, set the final timing belt tensioner as outlined in Timing Belt Tensioner Adjustment at the end of this procedure.

Timing Belt Tensioner Adjustment

Important: The following steps are the COMPLETION of adjusting the timing belt and must not be performed as a stand alone operation.

  1. With the J 42069-10 in place locking the crankshaft at TDC:

  2. Object Number: 826216  Size: SH
    1.1. Loosen the timing belt tensioner eccentric locking nut.
    1.2. Turn the eccentric counterclockwise to full stop, then back until the reference mark is 3-4 mm (0.118-0.157 in) ABOVE the reference mark on the flange.

    Tighten
    Tighten the timing belt tensioner locking nut to 20 N·m (15 lb ft).

  3. If the timing belt upper idler pulley bolts have not been previously torqued to specification:
  4. Tighten
    Tighten the timing belt idler pulley bolts while holding the eccentric in place with the J 42069-40 adjusting wrench to prevent movement, to 40 N·m (30 lb ft).

  5. Remove all checking tools.
  6. As a final inspection, once again rotate the engine in the clockwise direction 2 revolutions until reaching 60 degrees BTDC.
  7. Install the J 42069-10 crankshaft locking tool to the crankshaft drive gear with the knurled bolt.
  8. Use the J 42098 to carefully turn the crankshaft until the lever of the J 42069-10 firmly contacts the water pump pulley flange.
  9. Secure the moveable lever of the tool to the water pump pulley flange.
  10. Inspect the alignment of the reference marks on the camshaft gears with the notches on the rear timing belt cover, as well as, the mark on the crankshaft gear with the mark on the oil pump housing.
  11. Inspect the alignment of the marks on all four camshaft gears in reference to the marks on the J 42069-20 checking gage.
  12. Repeat the Timing Belt Timing Procedure again if the marks do not align.
  13. Continue with the engine reassembly if further timing belt adjustment is not needed.