REMOVAL & INSTALLATION
It may be necessary to remove the radiator on some models, to gain the necessary room.All Engines Except 20R and 22R
- Remove the oil pan, as outlined in the appropriate preceding section.
- Unbolt the oil pump securing bolts and remove it as an assembly.
- Installation is the reverse of removal.
- Remove the oil pan as previously outlined.
- Unfasten the three bolts which secure the oil strainer.
- Remove the drive belts, the pulley bolt, and the crankshaft pulley.
- Unfasten the bolts which secure the oil pump housing to the timing chain cover, and remove the pump assembly.
- Remove the oil pump drive spline and the rubber O-ring.
- Installation is performed in the reverse order of removal. Apply sealer to the top oil pump housing bolt. Use a new oil strainer gasket.
There are three types of oil pumps. The 4M-E and 5M-E engines use a geared impeller type pump. The 20R and 22R series use an automatic transmission type gear pump. The 8R-C and 18R-C use a trochoid rotary type pump. In both gear types, there is a drive gear and a driven gear; pump inspection procedures are very similar on both types. Inspection of the trochoid pumps is similar to the gear types.8R-C and 18R-C Engines
- Remove the oil pump.
- Disassemble the pump by removing the oil strainer, relief valve plug, gasket, spring, and relief valve from the pump cover. Remove the cover, drive shaft and driven rotor from the pump body.
- Clean all parts in solvent and inspect for unusual wear and/or damage. Replace any parts if necessary. Pay special attention to the pump shaft, drive and driven rotors.
- Check drive-to-driven rotor tip clearance, using a feeler gauge. If clearance exceed 0.008 inches (0.203mm), replace the rotors as a set.
- Using the feeler gauge and a steel square or steel block, check side clearance between the rotor and pump cover surface. Replace the rotor and/or body if clearance exceeds 0.006 inches (0.152mm).
- Measure the clearance between the driven rotor and pump body; clearance should be less than 0.008 inches (0.203mm). Replace the body and/or rotors as a set if clearance exceeds this figure.
- Reassemble the pump in the reverse order of disassembly. Stamped marks are provided on the drive rotor and driven rotor, and should face toward the pump cover side (toward the underneath of the engine when installed).
- Check pump operation by immersing the suction end of the pump in clean engine oil and turning the shaft counterclockwise by hand. Oil should come out of the discharge hole. Close the discharge hole with your thumb, and turn the shaft. The shaft should be difficult to turn. Use a flat bladed tool to rotate the rotor shaft.
- Remove the oil pump.
- Matchmark the drive and driven gears before disassembling the pump.
- Disassemble the pump by unscrewing the relief valve plug and removing the spring and relief valve piston. Remove the drive and driven gears, and clean all parts in solvent. Inspect all parts for unusual wear and replace if necessary.
- Align the matchmarks and assemble the gears into the pump body. Using a feeler gauge, measure the clearance between inches (0.203mm), replace the gear and/or body.
- Measure the clearance between both gear tips and the crescent with a feeler gauge. If clearance exceeds 0.012 inches (0.304mm), replace the gears and/or body.
- Using a feeler gauge and steel square or flat steel block, measure the gear side clearance as shown. If the clearance is greater than 0.15 inches (3.81mm), replace the gears and/or body.
- Assemble the pump in the reverse order of disassembly.
- Remove the oil pump.
- Disassemble the pump by removing the relief valve plug, spring and relief valve. Remove the pump cover and driven gear. Using needlenose pliers, remove the snapring and remove the spacer, drive shaft gear, key and shaft sub-assembly.
- Clean all parts in solvent, and inspect for scoring or other unusual wear. Replace any part that looks worn or damaged.
- Measure driven gear-to-body clearance with a feeler gauge; if clearance exceeds 0.008 inches (0.203mm), replace the gear and/or body.
- Insert a feeler gauge between the meshing faces of the two gears (gear backlash measurement). If the backlash is greater than 0.035 inches (0.889mm), replace the shaft sub-assembly and/or driven gear.
- Using a feeler gauge and steel square or flat steel block, measure the side clearance. If clearance is greater than 0.0059 inches (0.149mm), replace the gears and/or pump body.
- Reassemble the pump in the reverse order of disassembly. Check pump operation by immersing the suction end of the pump in clean engine oil and turning the shaft counterclockwise by hand. Oil should come out of the discharge hole. Close the discharge hole with your thumb, and turn the shaft. The shaft should be difficult to turn.