CAUTION: Oil pump pressure relief valve and spring should not be removed from the oil pump. If these components are disassembled and or removed from the pump the entire oil pump assembly must be replaced.
1. Remove the pump cover.
2. Clean all parts thoroughly. The mating surface of the oil pump housing should be smooth. If the oil pump cover is scratched or grooved the oil pump assembly should be replaced.
3. Slide the outer rotor into the body of the oil pump. Press the outer rotor to one side of the oil pump body and measure the clearance between the outer rotor (2) and the body. If the measurement is 0.235 mm (0.009 in.) or greater the oil pump assembly must be replaced.
4. Install the inner rotor into the oil pump body. Measure the clearance between the inner (3) and outer (1) rotors. If the clearance between the rotors is.150 mm (0.006 in.) or greater the oil pump assembly must be replaced.
5. Place a straight edge (1) across the body of the oil pump (between the bolt holes), using a feeler gauge (2), measure the clearance between the straightedge and the rotors. If the clearance is.095 mm (0.0038 in.) or greater the oil pump must be replaced.
6. Install the pump cover and tighten retainers to 15 N.m (11 ft. lbs.)
NOTE: The 6.4L oil pump is serviced as an assembly. There are no Chrysler part numbers for sub-assembly components. In the event the oil pump is not functioning or out of specification it must be replaced as an assembly.