GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • OTC 1726 , Km 412 Engine Overhaul Stand.
    • J 42492-A KM 421-A Timing Belt Adjuster
    • J 45059 Angle Meter, KM-470-B Angular Torque Gage
    • J 36972 or KM 635 Crankshaft Rear Oil Seal Installer

Removal Procedure


    Object Number: 1289673  Size: SH

    Important: Take extreme care to prevent any scratches, nicks, or damage to the camshafts.

  1. Remove the engine. Refer to Engine Replacement .
  2. Remove the flywheel or flexible plate bolts.
  3. Remove the flywheel or the flexible plate.

  4. Object Number: 1289674  Size: SH
  5. Remove the crankshaft rear oil seal.
  6. Mount the engine assembly on the OTC 1726 .

  7. Object Number: 1263767  Size: SH
  8. Remove the front timing belt cover bolts.
  9. Remove the front timing belt cover.
  10. Remove the crankshaft pulley bolts.
  11. Remove the crankshaft pulley.

  12. Object Number: 1263615  Size: SH
  13. Loosen the timing belt automatic tensioner bolt.
  14. Rotate the timing belt automatic tensioner hex-key clockwise to release the tension.
  15. Remove the timing belt idler pulleys bolt and nut.
  16. Remove the timing belt idler pulleys.

  17. Object Number: 1263617  Size: SH
  18. Remove the timing belt.
  19. Remove the engine mount retaining bolts.
  20. Remove the engine mount.

  21. Object Number: 1263768  Size: SH
  22. Disconnect the engine ventilation hoses from the camshaft cover.
  23. Remove the oil filler cap.
  24. Remove the spark plug cover bolts.
  25. Remove the spark plug cover.
  26. Remove the camshaft cover nuts.
  27. Remove the camshaft cover washers.
  28. Remove the camshaft cover and the camshaft cover gasket.

  29. Object Number: 1263772  Size: SH

    Important: Take extreme care to prevent any scratches, nicks or damage to the camshafts.

  30. While holding the intake camshaft firmly in place, remove the intake camshaft bolt.
  31. Remove the intake camshaft gear.
  32. While holding the exhaust camshaft firmly in place, remove the exhaust camshaft bolt.
  33. Remove the exhaust camshaft gear.

  34. Object Number: 1263769  Size: SH
  35. Remove the crankshaft timing belt gear bolt.
  36. Remove the crankshaft timing belt gear.

  37. Object Number: 1263771  Size: SH
  38. Remove the rear timing belt cover screws/bolt.
  39. Remove rear the timing belt cover.

  40. Object Number: 1289676  Size: SH
  41. Rotate the engine on the OTC 1726 .

  42. Object Number: 1263774  Size: SH
  43. Remove the oil pan retaining bolts.
  44. Remove the oil pan.
  45. Remove the oil suction pipe and support bracket bolts.
  46. Remove the oil suction pipe.
  47. Remove the oil pan scraper.
  48. Remove the crankshaft bearing bridge bolts.
  49. Remove the crankshaft bearing bridge.

  50. Object Number: 1289678  Size: SH
  51. Remove the oil pump retaining bolts.
  52. Remove the oil pump.

  53. Object Number: 1289679  Size: SH
  54. Mark the order of the connecting rod bearing caps.
  55. Remove the connecting rod bearing cap bolts for all of the pistons.
  56. Remove the connecting rod bearing caps and the lower connecting rod bearings.

  57. Object Number: 1263777  Size: SH
  58. Mark the order of the crankshaft bearing caps.
  59. Remove the crankshaft bearing cap bolts.
  60. Remove the crankshaft bearing caps and the lower crankshaft bearings.
  61. Remove the crankshaft.
  62. Caution: Refer to Safety Glasses Caution in the Preface section.

  63. Clean the parts, as needed.

Installation Procedure


    Object Number: 1289680  Size: SH
  1. Coat the crankshaft bearings with the engine oil.
  2. If replacing the crankshaft, transfer the pulse pickup snesor disc to the new crankshaft.

  3. Object Number: 1289681  Size: SH
  4. Install the crankshaft.
  5. Install the lower crankshaft bearings in the bearing caps.
  6. Inspect the crankshaft end play with the crankshaft bearings installed.
  7. Check for permissible crankshaft end play. Refer to Engine Mechanical Specifications .

  8. Object Number: 1289682  Size: SH
  9. With the crankshaft mounted on the front and the rear crankshaft bearings, check the middle crankshaft journal for permissible out-of-round (runout). Refer to Engine Mechanical Specifications .

  10. Object Number: 1289683  Size: SH

    Important: Grease the crankshaft journals and lubricate the crankshaft bearings slightly so that the plastic gauging thread does not tear when the crankshaft bearing caps are removed.

  11. Inspect all of the crankshaft bearing clearances using a commercially available plastic gauging (ductile plastic threads).
  12. Cut the plastic gauging threads to the length of the bearing width. Lay them axially between the crankshaft journals and the crankshaft bearings
  13. Notice: Refer to Fastener Notice in the Preface section.

  14. Install the crankshaft bearing caps and the bolts.
  15. Tighten
    Tighten the crankshaft bearing cap bolts to 50 N·m (37 lb ft) plus 45 degrees plus 15 degrees.


    Object Number: 1289685  Size: SH
  16. Remove the crankshaft bearing cap bolts and the caps.
  17. Measure the width of the flattened plastic thread of the plastic gauging using The scale printed on the plastic gaging packaging. Plastic gauging is available for different tolerance ranges.
  18. Inspect the bearing clearance for permissible tolerance ranges. Refer to Engine Mechanical Specifications .

  19. Object Number: 1289686  Size: SH
  20. Apply a bead of adhesive sealing compound to the grooves of the crankshaft bearing caps.
  21. Install the crankshaft bearing caps to the engine block.
  22. Tighten the crankshaft bearing caps using new bolts.
  23. Tighten
    Tighten the crankshaft bearing cap bolts to 50 N·m (37 lb ft) using a torque wrench. Use J 45059 to tighten the crankshaft bearing 45 degrees plus 15 degrees.


    Object Number: 1289683  Size: SH

    Important: Grease the connecting rod journals and lubricate the connecting rod bearings slightly so that the plastic gauging thread does not tear when the connecting rod bearing caps are removed.

  24. Inspect all of the connecting rod bearing clearances using a commercially available plastic gauging (ductile plastic threads).
  25. Cut the plastic gauging threads to the length of the connecting rod bearing width. Lay them axially between the connecting rod journals and the connecting rod bearings.
  26. Install the connecting rod bearing caps.
  27. Tighten
    Tighten the connecting rod bearing cap bolts to 25 N·m (18 lb ft) using a torque wrench. Use the J 45059 to tighten the connecting rod bearing cap bolts 30 degrees plus 15 degrees.


    Object Number: 1289685  Size: SH
  28. Remove the connecting rod bearing caps.
  29. Measure the width of the flattened plastic thread of the plastic gauging using the scale printed on the plastic gaging packaging. (Plastic gauging is available for different tolerance ranges.)
  30. Inspect the bearing clearance for permissible tolerance ranges. Refer to Engine Mechanical Specifications .

  31. Object Number: 1289653  Size: SH
  32. Install the connecting rod bearing caps to the connecting rods.
  33. Tighten the connecting rod bearing caps using new bolts.
  34. Tighten
    Tighten the connecting rod bearing cap bolts to 35 N·m (26 lb ft) using a torque wrench. Use J 45059 to tighten the connecting rod cap bolts 45 degrees plus 15 degrees.


    Object Number: 1263775  Size: SH
  35. Install the oil pump.
  36. Install the oil pump retaining bolts.
  37. Tighten
    Tighten the oil pump retaining bolts to 10 N·m (89 lb in).


    Object Number: 1263794  Size: SH
  38. Install the lower block support bracket and bolts.
  39. Tighten
    Tighten the bracket bolts to 20 N·m (15 lb ft).

  40. Install the lower block support bracket splash shield and bolts.
  41. Tighten
    Tighten the splash shield bolts to 20 N·m (15 lb ft).

  42. Install the oil suction pipe.
  43. Install the oil suction pipe bolts.
  44. Tighten
    Tighten the oil suction pipe bolts to 10 N·m (89 lb in).

  45. Install the oil suction pipe support bracket bolts.
  46. Tighten
    Tighten the support bracket bolts to 10 N·m (89 lb in).


    Object Number: 1263796  Size: SH
  47. Coat the new oil pan gasket with sealant.
  48. Install the oil pan gasket to the oil pan.
  49. Install the oil pan.
  50. Install the oil pan retaining bolts.
  51. Tighten
    Tighten the oil pan retaining bolts to 10 N·m (89 lb in).


    Object Number: 1289676  Size: SH
  52. Rotate the engine on the engine overhaul stand OTC 1726 .

  53. Object Number: 1263798  Size: SH
  54. Install the rear timing belt cover.
  55. Install the rear timing belt cover bolts.
  56. Tighten
    Tighten the cover bolts to 10 N·m (89 lb in).

  57. ll the crankshaft gear and bolt using J 45059 .
  58. Tighten
    Tighten the mount retaining bolts to 130 N·m (96 lb ft) + 40 degrees + 15 degrees.

  59. Install the engine mount and retaining bolts.
  60. Tighten
    Tighten the mount retaining bolts to 30 N·m (22 lb ft).


    Object Number: 1263615  Size: SH
  61. Install the timing belt automatic tensioner.
  62. Install the timing belt automatic tensioner bolts.
  63. Tighten
    Tighten the timing belt automatic tensioner bolts to 25 N·m (18 lb ft).

  64. Install the timing belt idler pulleys.
  65. Install the timing belt idler pulley bolt and nut.
  66. Tighten
    Tighten the timing belt idler pulley bolt and nut to 40 N·m (30 lb ft).


    Object Number: 1291233  Size: SH

    Important: Take extreme care to prevent any scratches, nicks or damage to the camshafts.

  67. Install the intake camshaft gear.
  68. Install the intake camshaft gear bolt while holding the intake camshaft firmly in place.
  69. Tighten
    Tighten the intake camshaft gear bolt to 67.5 N·m (49 lb ft).

  70. Install the exhaust camshaft gear.
  71. Install the exhaust camshaft gear bolt while holding the exhaust camshaft firmly in place.
  72. Tighten
    Tighten the exhaust camshaft gear bolt to 67.5 N·m (49 lb ft).


    Object Number: 1263768  Size: SH
  73. Install the timing belt. Refer to Timing Belt Replacement .
  74. Adjust the timing belt tension. Refer to Timing Belt Inspection .
  75. Apply a small amount of gasket sealant to the corners of the front camshaft caps and to the top of the rear camshaft cover-to-cylinder head seal.
  76. Install the camshaft cover and the camshaft cover gasket.
  77. Install the camshaft cover washers.
  78. Install the camshaft cover bolts.
  79. Tighten
    Tighten the camshaft cover bolts to 10 N·m (89 lb in).


    Object Number: 1263612  Size: SH
  80. Connect the ignition wires to the spark plugs.
  81. Install the oil filler cap.
  82. Connect the engine ventilation hose to the camshaft cover.
  83. Install the front timing belt covers.
  84. Install the upper and the lower front timing belt cover bolts.
  85. Tighten
    Tighten the upper and the lower front timing belt cover bolts to 10 N·m (89 lb in).

  86. Install the engine lifting device.
  87. Remove the engine from the engine overhaul stand OTC 1726 .

  88. Object Number: 1289760  Size: SH
  89. Install a new crankshaft rear oil seal using J 36972 or the KM-635 .

  90. Object Number: 1289762  Size: SH
  91. Install the flywheel or the flexible plate.
  92. Install the flywheel or the flexible plate bolts.
  93. Tighten
    Tighten the flywheel bolts to 35 N·m (25 lb ft). Use the J 45059 to tighten the flywheel bolts another 30 degrees plus 15 degrees. If the vehicle is equipped with an automatic transaxle, tighten the flexible plate bolts to 45 N·m (33 lb ft).

  94. Install the engine. Refer to Engine Replacement .