GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

  1. Clean all parts in approved cleaning solvent.
  2. Blow the parts dry with compressed air. Wear protective safety glasses and gloves.

Inspection Procedure

  1. Inspect the oil pump body for cracks or damage.
  2. Inspect the gears for pitting and wear.

Measurement Procedure

Important: If the clearances are excessive, replace the oil pump as an assembly.


    Object Number: 736655  Size: SH
  1. Measure the gear tooth to wall clearance. Clearance must not exceed 0.3 mm (0.012 in).

  2. Object Number: 736661  Size: SH
  3. Measure the drive gear shaft (1) and oil pump body clearance (2) using the following procedure:
  4. • Using a micrometer measure the drive gear shafts.
    • The measurements should be: 15.9 mm (0.626 in).
    • Use an inside micrometer to measure the cylinder block body bushing for the oil pump.
    • If the clearance between the gear shaft and the oil pump body or the cylinder block bushing exceeds 0.2 mm (0.008 in), both the oil pump and/or the cylinder block bushing may have to be replaced.