Overhaul

Engine Oil Pump Overhaul

View

1. Oil Pump Exploded View

Exploded View





Disassembly

NOTE: Refer to the Exploded View if needed during this procedure.

1. Engine Oil Pump Balancer Shaft End Play - Inspection

1. Zero the dial indicator against the end of the rear balancer shaft, then push the rear balancer shaft back and forth and read the end play.











2. Engine Oil Pump Housing





1. 1. Remove the pump housing.

3. Engine Oil Pump Balancer Shaft





1. Remove the upper balancer shaft holder (with bearings) (A) and the baffle plates (B).

2. Remove the front balancer shaft (C) and the rear balancer shaft (D).

4. Engine Oil Pump - Inspection

1. Align the tip of the inner rotor tooth (A) with the mark (B) on the outer rotor, then check the inner rotor-to-outer rotor radial clearance between the inner rotor and the outer rotor. If the inner rotor-to-outer rotor radial clearance exceeds the service limit, replace the oil pump.












2. Check the pump housing-to-rotor axial clearance between the rotor (A) and the pump housing (B). If the pump housing-to-rotor axial clearance exceeds the service limit, replace the oil pump.












3. Check the pump housing-to-outer rotor radial clearance between the outer rotor (A) and the pump housing (B). If the pump housing-to-outer rotor radial clearance exceeds the service limit, replace the oil pump.











5. Engine Oil Pump Balancer Shaft - Inspection

1. Measure the inner diameters of the No. 1 bearing for the front balancer shaft hole and the rear balancer shaft hole.







Front





Rear





Front





Rear





2. Measure the diameters of the No. 1 journal on the front balancer shaft and the rear balancer shaft.





3. Clean both balancer shaft No. 2 journals and the bearing halves with a clean shop towel, then place both balancer shafts into the balancer holder.

4. Place one strip of plastigage across each No. 2 journal.

5. Reinstall the bearings and the upper balancer shaft holder, then tighten the bolts.
NOTE: Do not rotate the balancer shafts during inspection.

6. Remove the upper balancer shaft holder and the bearings again, and measure the widest part with the plastigage. If the balancer shaft No. 2 journals oil clearance is out-of-tolerance, install new bearings, and recheck. If it is still out-of-tolerance, replace the balancer shafts.











Reassembly

NOTE: Refer to the Exploded View if needed during this procedure.

1. Engine Oil Pump Balancer Shaft





1. Align the punch mark on the rear balancer shaft in the center of the two punch marks on the front balancer shaft, then install the balancer shafts on the lower balancer shaft holder.





2. Apply new engine oil to the threads of the 8 mm bolts (A).

3. Install the upper balancer shaft holder (B) with a new O-ring (C).

2. Engine Oil Pump Housing





1. Install the pump housing.