Oil Pump: Service and Repair

REMOVAL
1. Remove oil pan as described under ``Oil Pan, Replace.''
2. Remove oil pump attaching bolts and nuts, then the oil pump and screen as an assembly.

Fig. 13 Exploded view of oil pump:

DISASSEMBLY
1. Drain residual oil from pump.
2. Remove suction pipe and screen assembly from pump.
3. Remove pump cover attaching screws, then the pump cover and gears, Fig. 13.
4. Remove pump regulator valve. Remove plug, spring and ball from valve.

Fig. 14 Measuring oil pump gear backlash:

Fig. 15 Measuring oil pump gear pocket:

Fig. 16 Measuring oil pump gears:

INSPECTION
1. Inspect pump housing and cover for wear or damage, and replace if necessary.
2. Inspect pressure regulator valve for scoring or sticking. Burrs may be removed with a fine oil stone, however more extensive damage requires replacement of valve.
3. Inspect idler gear shaft for wear or damage, and replace if necessary.
4. Inspect pressure regulator spring for lack of tension or distortion, and replace if necessary.
5. Inspect suction pipe and screen, and clean or replace as necessary. If suction pipe is permanently pressed into the pump body, and if it is loose or has been removed, a new pipe must be installed.
6. Inspect gears and driveshaft for wear or damage and replace as necessary.
7. Install gears into housing and measure gear backlash, Fig. 14. Backlash should measure .009-.015 inch.
8. Measure pump housing gear pocket depth and diameter, Fig. 15. Depth should measure .995-.998 inch and diameter 1.503-1.506 inches.
9. Measure length and diameter of gears, Fig. 16. Length of both gears should be .999-1.002 inch and diameter should be 1.496-1.500 inches.

Fig. 17 Measuring oil pump gear side clearance:

Fig. 18 Measuring oil pump gear end clearance:

10. Measure gear side clearance, Fig. 17. Side clearance should measure no more than .004 inch.
11. Measure gear end clearance, Fig. 18. End clearance should be .002-.005 inch.
12. If any measurements taken in steps 7 through 11 are not within specifications, replace oil pump components as necessary.




ASSEMBLY
1. Lubricate all internal components with clean engine oil and pack all pump cavities with petroleum jelly.
2. Install pump gears into housing.
3. Install pump cover, pressure regulator valve and spring. Torque cover attaching bolts to 10 ft. lbs. and the pressure regulator valve plug to 15 ft. lbs.
4. Apply suitable sealer to new pipe, then tap pipe into position using a plastic hammer and tool No. J-8369.

INSTALLATION
1. Align oil pump shaft with tang on oil pump driveshaft, then install pump on block, positioning pump flange over oil pump driveshaft lower bushing.
2. Install pump attaching bolts and torque to 20 ft. lbs.
3. Install oil pan.