Oil Pump: Testing and Inspection

CLEANING
Wash all parts in a solvent and dry them thoroughly with compressed air. Use a brush to clean the inside of the oil pump housing and the pressure relief valve chamber. Remove all dirt and metal particles.

INSPECTION
1. Place Straight Edge 303-D039 (D83L-4201-A) or equivalent across mounting surface of engine front cover and measure for wear or warpage using a feeler gauge. If surface is out of flat by more than 0.04 mm (0.0016 inch), replace engine front cover.
2. Check the inside of the oil pump and filter body and the inner and outer gears for damage or excessive wear.
3. Check the mating surface of the oil pump and filter body for wear. Minor scuff marks are normal but if the engine front cover, gears or oil pump and filter body surfaces are excessively worn, scored or grooved, replace the engine front cover or oil pump and filter body. Remove minor imperfections with an oil stone.
4. Inspect oil pump cover gasket surface on engine front cover. Remove any gasket material, burrs or nicks. Visually inspect O-rings for any nicks and/or cuts and replace as necessary.
5. Measure thickness of gear using a micrometer. Gear should be 31.980-31.955 mm (1.259- 1.258 inches) thick.
- If gear is less than 31.955 mm (1.258 inches) thick, replace gear.
- If gear thickness is within specification, it may be necessary to replace the oil pump and filter body.
- If thickness of gear is within specified limits, go to Step 6.
6. Measure depth of the gear pocket in the oil pump and filter body. Depth should be 32.04-31.99 mm (1.261-1.259 inches).
- If depth is more than 31.99 mm (1.259 inches), replace oil pump and filter body.
7. Measure side clearance by inserting Feeler Gauge 303-D027 (D81L-4201-A) or equivalent between a gear tooth and side wall of the gear pocket.
- Clearance should be a maximum of 0.13 mm (0.005 inch) and gears should be free to turn.
- If clearance is greater than 0.13 mm (0.005 inch), go to Step 8.
8. Measure diameter of gear using a micrometer. Gear should be 42.342-42.291 mm (1.667-1.665 inches).
- If gear is less than 42.291 mm (1.665 inches) wide, replace gear and measure clearance as described in Step 7.
- If diameter of gear is within specified limits, go to Step 9.
9. Measure diameter of gear pocket in the oil pump and filter body. The diameter should be 42.54-42.46 mm (1.675-1.672 inches).
- If diameter is less than 42.46 mm (1.672 inches), replace oil pump and filter body and measure clearance as specified in Step 7.