For models from 1999 through 2005, begin by removing the
Timing Belt, followed by the oil pan to access the oil pickup and its gasket. Next, remove the access plug on the left side of the engine block and use a screwdriver to lock the balance shaft into position. After that, take out the left balance shaft and oil pump sprocket bolt, then remove the front case and oil pump housing. Detach the oil pump cover and lift out the oil pump gears, ensuring to scrape off any sealant and old gasket material from the pump body and engine block, followed by cleaning the mating surfaces. Inspect the oil pump for wear; if there are any concerns, replacing it is advisable, and clearances can be measured with a feeler gauge. For installation, position the oil pump gears while aligning the timing marks, then prime the pump with petroleum jelly. Install new oil seals and gaskets, including the O-ring in the front case, and tighten the bolts in a criss-cross pattern to avoid warping. Secure the lower drive sprocket retaining bolt and reinstall the timing belts. Finally, add oil to the correct level, start the engine, and check for oil pressure and leaks. For models from 2006 and later, the oil pump is integrated into the balance shaft module, which must be removed as part of the timing chain removal procedure, and the entire module needs to be replaced since the oil pump is not serviced separately.