Oil Pump: Service and Repair

Fig. 39 Oil pump installation (Typical):

REPLACEMENT

1. Remove oil pan as outlined previously.
2. Remove oil pump to rear main bearing cap attaching bolts, Fig. 39.
3. Remove oil pump and driveshaft extension.
4. Reverse procedure to install. Torque attaching bolts to 35 ft. lbs.

Fig. 40 Oil pump disassembled:

SERVICE

Disassembly

1. Remove oil pump driveshaft extension, Fig. 40. Do not attempt to remove washers from driveshaft extension. The driveshaft extension and washers is serviced as an assembly.
2. Remove cotter pin, spring and pressure regulator valve. Apply pressure on pressure regulator bore before removing cotter pin since the spring is under pressure.
3. Remove oil pump cover attaching screws and the oil pump cover and gasket.
4. Remove drive gear and idler gear from pump body.

Fig. 41 Oil pump driveshaft extension. V8 engines:

Inspection

1. Check gears for scoring or other damage, replace if necessary.
2. Proper end clearance is .0005-.0075 inch.
3. Check pressure regulator valve, valve spring and bore for damage. Proper bore to valve clearance is .0025-.0050 inch.
4. Check extension shaft ends for wear, Fig. 41.



Assembly

1. Install gears and shaft in oil pump body.
2. Check gear end clearance by placing a straightedge over the gears and measure the clearance between the straightedge and gasket surface. If end clearance is excessive, check for scores in cover that would bring the clearance over specified limits.
3. Install cover and torque attaching screws to 8 ft. lbs.
4. Install pressure regulator valve, closed end first, into bore, then the valve spring and cotter pin.