Oil Pump: Service and Repair

Fig. 22 Oil Pump:

REMOVAL & INSPECTION

1. Remove front cover, refer to FRONT COVER procedure.
2. Remove oil filter adapter, pressure regulator valve and spring.
3. Remove oil pump cover attaching screws, then the cover and gears, Fig. 22.
4. Check pump cover and housing for cracks, scoring, porous or damaged casting, damaged threads or excessive wear or galling. Replace as required.
5. Check pressure regulator valve for scoring, burrs or sticking in valve bore. Replace as required.
6. Check pressure regulator valve spring for tension loss or bending. Replace spring as required.
7. Check gears for chipping galling or excessive wear. Replace as required.

Fig. 23 Measuring Oil Pump Inner Gear Tip Clearance:

Fig. 24 Measuring Oil Pump Outer Gear Diameter Clearance:

Fig. 25 Measuring Oil Pump Gear End Clearance:

ASSEMBLY & INSTALLATION

1. Measure oil pump inner gear tip clearance, Fig. 23. Maximum clearance should be .006 inch.
2. Measure oil pump outer gear diameter clearance, Fig. 24. Clearance should be .008-.015 inch.
3. Measure oil pump gear end clearance with gear dropped in housing, Fig. 25. Clearance should be .0010-.0035 inch.
4. Measure pressure regulator valve for valve to bore clearance of .0015-.003 inch.
5. Lubricate all gears with clean motor oil, then install gears in housing.
6. Pack pump cavity with suitable petroleum jelly.
7. Install pump cover and cover attaching screws. Tighten cover attaching screws to specifications.
8. Install pressure regulator valve and spring.
9. Install oil filter adapter using a new gasket. Torque oil filter adapter attaching bolts to specifications.
10. Install front cover on engine. During front cover installation, ensure inner pump gear is properly engaged on crankshaft sprocket.