Mopar 68138644AA Engine Oil Pump

Before removal of the oil pump, it is advisable to disconnect the negative terminal of the battery from the remote ground terminal of battery. Lift the front of the vehicle and prop it up on jackstands and engage the parking brake and place wheel chocks behind the rear wheels. Remove the engine oil, then plastic bolts from the lower splash and the shield. Then remove lower and upper oil pans, then the fastener and the oil pump pick-up tube with O-ring to be discarded. Remove the oil pump solenoid electrical connection from the engine, push the locking tab and fit the connector into the block carefully as it will be in the way of the tensioner mounting bolt. Take out the bolts of the oil pump timing gear splash shield, as well as the splash shield itself; gently push the oil pump chain tensioner away from the chain so that you can fit a 3 mm Allen wrench into the housing to hold the chain securely. Position arrow marks to the chain and oil pump gear, secure the gear from turning and then loosen and take out the T45 Torx sprockets mounting bolt and the gear. Screw out the Allen wrench for the tensioner to provide a way for the release and then the spring should be taken off the dowel pin together with the tensioner off the oil pump. Last of all, take out the oil pump mounting bolts and the pump, itself. To clean, merely wash them and for assessment, check the rotors for cracks and the pump cover and timing chain cover for damages; replace the whole assembly if so. Check that the body of the oil pump is warped, and that the thickness of the outer and inner rotors is correct and that the clearances between the outer rotor and the housing, as well as the space between the lobes of the inner and outer rotors are accurate. If any of these measurements is beyond the stated level, it is advisable to replace the pump. For installation, first of all, fix the oil pump on the engine block with the help of the aligning dowels and then tighten the mounting bolts of the oil pump thereafter, fit the oil pump chain tensioner on the pivot and then hold this tensioner by means of space key of 3mm. Align the timing chain gear on the bottom of the oil pump to the opening of the oil pump shaft and fasten the T45 mounting bolt provided with the gear with a view to have the same direction of the gear as before being subjected to removal. Swivel the oil pump solenoid into position to fit it properly, then position and bolt the timing gear splash, also tighten the bolts. Reverse all the above removal procedures and then you fill up the engine with oil and replace the oil filter.

Remove the oil pan and then take out the two oil pump attaching bolts from the engine block. Detach the oil pump and strainer assembly from the block. If the pump is defective, replace it with a new one; during a complete engine overhaul, install a new oil pump instead of reusing or attempting to rebuild the original. For four-cylinder engines, install the oil pump by turning the shaft so the gear tang mates with the slot on the lower end of the distributor shaft, ensuring it slides easily into place. If it doesn't, adjust the tang until it aligns properly. For six-cylinder engines, turn the shaft to align the gear tang with the slot on the lower end of the distributor shaft for 1987 through 1999 models, or with the camshaft position sensor drive shaft for 2000 models, ensuring it also slides easily into place. Finally, install the pump attaching bolts and tighten them to the specified torque.

Remove the timing belt, timing belt covers, and the crankshaft front seal. Next, take off the oil pan and pick-up tube/screen assembly. Detach the oil pump assembly from the engine by removing the mounting bolts; if it doesn't come off easily, tap it gently with a soft-faced hammer or pry on a casting boss. Extract the crankshaft oil seal from the oil pump using a screwdriver wrapped in a rag. Remove the mounting screws and the cover, then take out the inner and outer rotor from the body. Clean all components, including the block surfaces, with solvent and inspect for excessive wear or damage. To disassemble the relief valve, take out the cap bolt, washer, spring, and relief valve, checking the piston sliding surface and valve spring for damage; if either is damaged, replace them as a set, otherwise reassemble the parts, coat them with oil, and reinstall in the oil pump body, tightening the cap bolt. Check the clearance of the oil pump components with a micrometer and feeler gauge. For installation, lubricate the housing and rotors with clean engine oil, install both rotors in the body, and prime the oil pump by filling the rotor cavities with clean engine oil. Install the cover and tighten the screws to the specified torque. Place a new O-ring in the oil discharge passage, apply sealant to the oil pump body, and raise the pump assembly to the block, aligning the rotor flats with the crankshaft flats before tightening the bolts to the specified torque. Install the crankshaft seal, pick-up tube/strainer assembly, oil pan, crankshaft sprocket, rear timing belt cover, and timing belt. Finally, install a new oil filter and engine oil, start the engine, check for oil pressure and leaks, and recheck the engine oil level.

Remove the oil pan and the timing chain cover, then take off the oil pump cover from the timing chain cover by unscrewing the oil pump cover screws. Clean all parts thoroughly in solvent and inspect the rotors, pump cover, and timing chain cover for any nicks, scratches, or burrs, replacing the assembly if damaged. Use a straightedge and feeler gauge to measure the oil pump cover for warpage; if warped beyond the limit, replace the pump. Measure the thickness of both the outer and inner rotors with a micrometer, replacing the pump if either thickness is below the specified value. Insert the outer rotor into the timing chain cover/oil pump housing and measure the clearance between the rotor and housing with a feeler gauge; if the measurement exceeds the maximum allowable clearance, replace the pump. Install the inner rotor in the oil pump assembly with the chamfer facing the iron pump cover, then measure the clearance between the lobes of the inner and outer rotors; if the clearance is greater than the specified value, replace the pump. Check the clearance between the surface of the oil pump cover and the rotors using a straightedge and feeler gauge; if the clearance exceeds the limit, replace the pump. Install the pump cover and tighten the bolts to the specified torque, then install the timing chain cover and tighten its bolts to the specified torque. Complete the installation of the remaining components in reverse order of removal, and refill the engine with oil while changing the oil filter.