The crankshaft can only be accessed if the entire engine has been pulled out of the car accompanied with conditions such as; flywheel, crankshaft pulley, timing chain, engine oil pan, oil pump, oil filter,
Piston and connecting rod assemblies being removed. Before removing the crankshaft, face the crankshaft and with the help of dial indicator fix the end play of the crank shaft. With the crankshaft front (throws away from the water pump), set the indicator to zero; then, moving the shaft to the rear (throws towards the water pump), take the reading; the endplay should measure between 0.003 and 0.010 inches. If a dial indicator is not available feeler gauges can be used in order to measure clearance. Gradually undo the main bearing cap bolts, give the assembly a gentle tap with a soft-face hammer and then raise off the assembly. While lifting the crankshaft there is always advisable to do it with help because of its size. Before installing the crankshaft, clean both compartments of the engine block and the crankshaft and then turn the block upside down, take the main bearing cap assembly off, and clean the associated bearing surfaces. New upper main bearing inserts should be installed and checked for proper alignment of oil holes and also the thrust washers should be placed properly depending on the type of engine used. Clean the lower bearing inserts and they are then fitted into the main bearing cap assembly; they must fit perfectly and without any signs of wear or tear. Following the cleaning of the crankshaft, the crankshaft should be laid on the block and the main bearing oil clearance should be determined using Plastigage. The main bearing caps must be fitted without moving the Plastigage and the bolts must be tightened in the pattern that is recommended. The caps must be unscrewed to measure the Plastigage and to check the clearance; if beyond the limit, check for any interference, dirt or oil and if inserts are worn out they must be changed. Remove the Plastigage from the journals and bearing faces and lubricate the bearing surfaces with the assembly lube or fresh grease before putting back the crankshaft. Bolt the caps of the main bearing in position such that the arrows are facing forward, and tighten all the bolts. Check and recheck the crankshaft end-play and turn the crankshaft with your hands so that it can move with ease. Last of all, fit the new rear main oil seal into its respective position and sequence the engine as prescribed whereby the oil seal is fastened towards the front of the engine, so that the crankshaft will push it firmly into position.