GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 42038 Camshaft Holding Fixtures

Removal Procedure

  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .
  2. Remove the camshaft covers. Refer to Camshaft Cover Replacement .

  3. Object Number: 287745  Size: SH

    Important: You must install the J 42038 immediately after cam cover removal. The fixtures prevent unexpected camshaft rotation caused by valve spring pressure.

  4. Install the camshaft holding fixture J 42038 onto the ends of the camshaft. Rotate the engine to align the camshafts with the tool using the hex in the camshaft and an open wrench.

  5. Object Number: 264870  Size: SH
  6. When installed properly, the J 42038 will be fully seated on the camshaft ends with the camshaft flats parallel to the cam cover sealing surface.
  7. Remove the oil pan. Refer to Oil Pan Replacement .
  8. Remove the oil pump pipe and screen. Refer to Oil Pump Suction Pipe and Screen Assembly Replacement .

  9. Object Number: 235192  Size: SH
  10. Remove the camshaft drive chain tensioner (1) in order to remove the primary camshaft drive chain from the drive sprocket. Refer to Camshaft Drive Chain Tensioner Replacement .

  11. Object Number: 287881  Size: SH
  12. Remove the four oil pump assembly retaining bolts identified by the larger head size.
  13. Slide the oil pump assembly off the nose of the crankshaft with the drive sprocket in place.

  14. Object Number: 235168  Size: SH
  15. Remove the crankshaft sprocket from the oil pump assembly.
  16. Wrap the oil pump in a towel for safe, clean storage until inspection or assembly is necessary.
  17. If necessary, disassemble the oil pump. Refer to Oil Pump Disassemble .
  18. If necessary, clean and inspect the oil pump. Refer to Oil Pump Cleaning and Inspection .

Installation Procedure


    Object Number: 235168  Size: SH
  1. If necessary, assemble the oil pump. Refer to Oil Pump Assemble .
  2. Align the crankshaft sprocket splines with the oil pump gerotor and install the sprocket in the oil pump.

  3. Object Number: 287882  Size: SH
  4. Place the pump and sprocket assembly in position by rotating the crankshaft sprocket until the machined slot (2) is indexed with the drive pin (1) in the crankshaft.

  5. Object Number: 287888  Size: SH
  6. Slide the pump and sprocket onto the crankshaft until a positive stop is felt. Make sure the crankshaft sprocket is aligned with the drive pin in the crankshaft.
  7. Install the oil pump pipe and screen. Refer to Oil Pump Suction Pipe and Screen Assembly Replacement .
  8. Install the oil pan. Refer to Oil Pan Replacement .

  9. Object Number: 287885  Size: SH
  10. When properly installed, the crankshaft sprocket will protrude from the oil pump but the face of the sprocket will be located behind the machined step in the crankshaft as shown.
  11. Align the pump body with the mounting holes in the cylinder block.
  12. Install the oil pump retaining bolts.
  13. Tighten
    Tighten the oil pump retaining bolts to 25 N·m (18 lb ft).

  14. Install the primary camshaft drive chain over the drive sprocket. Refer to Camshaft Drive Chain Tensioner Replacement .

  15. Object Number: 235192  Size: SH

    Important: Make sure correct primary and secondary camshaft drive chain timing are maintained.

  16. Install the camshaft drive chain tensioner (1).

  17. Object Number: 264870  Size: SH
  18. Remove the J 42038 from the cylinder heads.
  19. Install the camshaft covers. Refer to Camshaft Cover Replacement .
  20. Install the engine front cover. Refer to Engine Front Cover Replacement .