GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 26900-2 Micrometer


    Object Number: 235471  Size: SH
  1. Use a caliper gage to measure the lifter bore diameter of the cylinder head.
  2. Lifter Bore Diameter
    31.000-31.025 mm (1.2205-1.2215 in)


    Object Number: 235495  Size: SH
  3. Use a J 26900-2 and measure the lifter diameter.
  4. Lifter Diameter
    30.966-30.976 mm (1.2191-1.2195 in)

  5. Subtract the lifter diameter measurement from the lifter bore diameter measurement to determine the oil clearance.
  6. Standard Oil Clearance
    0.024-0.059 mm (0.0009-0.0023 in)

    Maximum Oil Clearance
    0.079 mm (0.0031 in)

  7. If the oil clearance is greater than the maximum, replace the lifter. If the proper oil clearance is still greater than the maximum allowed, replace the cylinder head.