The crankshaft can be removed only after the engine is taken out of the vehicle. This is possible only when the flywheel, crankshaft pulley, timing belt, oil pan, oil pump body, oil filter and piston/connecting rod assemblies are removed. Prior to removal, measure the crankshaft endplay with a dial gauge against the crankshaft. Position the crankshaft rearward and zero the indicator. Then position the crankshaft forward and check the reading. It should typically be about 0.003 to 0.010 inch (0.076 to 0.254 mm). If a dial indicator is not available, clearance can be checked using feeler gauges. Gradually loosen the main bearing cap assembly bolts, gently tap the assembly with a soft-face hammer and lift it off. It is preferable to enlist the help of an assistant to lift the crankshaft. Before installation, make sure the engine block and crankshaft are clean and checked. Turn the block upside down, remove the main bearing cap assembly, and clean the bearing surfaces. Place the set of upper bearing inserts into the main bearing housing(journal) ensuring the oil holes are aligned. The set of lower inserts is placed in the main bearing cap assembly. The crankshaft needs to be cleaned after checking the oil holes for dirt. Position the crankshaft and check the main bearing oil clearance using Plastigage without disturbing it during assembly. Once the bolts have been tightened, take off the cap assembly and measure the Plastigage width against the scale. If clearances are not good, check for cleanliness and consider different inserts if necessary. Remove any Plastigage from the surfaces of the journal and insert. Apply a thin film of grease or engine assembly lube to the bearing surfaces. Then reinstall the crankshaft. Make sure that the main bearing assembly is correctly orientated, install it and tighten. Examine the crankshaft endplay again and rotate the crankshaft to check for binding, ensuring it rotates smoothly. Last step, replace the rear main oil seal.