GM 12588614 Engine Crankshaft

The crankshaft cannot be removed without the removal of the engine from the vehicle provided that the driveplate, crankshaft pulley, oil pan, timing chain as well as the piston/connecting rod assemblies have been removed. Prior to the crankshaft removal it is necessary to determine its end play by placing a dial indicator against a reference point on the crankshaft. Loosen the crankshaft warding by moving it to the rear and setting the indicator to zero before moving the warding to the front to adjust it to a standard of 0.003 to 0.010 inch. If you do not have dial indicator you may use the feeler gauges in order to get some clearance. For V8 engines start with side bolts, and turn the main bearing cap bolts gradually to the point where they can be removed by hand. For inline engines, then first, remove the stiffener plate if present and if you are planning to differentiate between main bearing caps, then mark these also if you have time. Slowly and gently, if possible with help, extract the crankshaft upwards and in again tighten the main bearing caps including the stiffener with a few turns. For installation, it is recommended to first check the condition of the engine block and the crankshaft and to remove possible dirt. Place the block in an inverted position, also, eliminate the original bearing inserts, or the projected surfaces, and wash them appropriately. New upper main bearing inserts should be fitted and to ensure the oil holes are in the correct alignment; place the lower ones into the main bearing caps. Inspect the oil clearance limit by run-in Plastigage verifying that it is standard. If not, check for cleanliness, and bear in mind different sizes of bearings are available if needed. In the process of operation, Plastigage is used to measure the amount of end play to ensure that after it is wiped off, place a thin layer of grease on the bearing surfaces and then re-install the crankshaft. The surfaces of the bearing inserts should be cleaned and lubricant applied before the main bearing caps are bolted on. After that tighten the bolts in the correct sequence and again check the crankshaft end play. Ensure that the crankshaft rotate with ease if not then it is an indication that it is bound. Last of them is to fit the new rear main oil seal into the retainer, however do not fit this retainer until the balance shafts are fitted.

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.

The crankshaft cannot be removed without the removal of the engine from the vehicle provided that the driveplate, crankshaft pulley, oil pan, timing chain as well as the piston/connecting rod assemblies have been removed. Prior to the crankshaft removal it is necessary to determine its end play by placing a dial indicator against a reference point on the crankshaft. Loosen the crankshaft warding by moving it to the rear and setting the indicator to zero before moving the warding to the front to adjust it to a standard of 0.003 to 0.010 inch. If you do not have dial indicator you may use the feeler gauges in order to get some clearance. For V8 engines start with side bolts, and turn the main bearing cap bolts gradually to the point where they can be removed by hand. For inline engines, then first, remove the stiffener plate if present and if you are planning to differentiate between main bearing caps, then mark these also if you have time. Slowly and gently, if possible with help, extract the crankshaft upwards and in again tighten the main bearing caps including the stiffener with a few turns. For installation, it is recommended to first check the condition of the engine block and the crankshaft and to remove possible dirt. Place the block in an inverted position, also, eliminate the original bearing inserts, or the projected surfaces, and wash them appropriately. New upper main bearing inserts should be fitted and to ensure the oil holes are in the correct alignment; place the lower ones into the main bearing caps. Inspect the oil clearance limit by run-in Plastigage verifying that it is standard. If not, check for cleanliness, and bear in mind different sizes of bearings are available if needed. In the process of operation, Plastigage is used to measure the amount of end play to ensure that after it is wiped off, place a thin layer of grease on the bearing surfaces and then re-install the crankshaft. The surfaces of the bearing inserts should be cleaned and lubricant applied before the main bearing caps are bolted on. After that tighten the bolts in the correct sequence and again check the crankshaft end play. Ensure that the crankshaft rotate with ease if not then it is an indication that it is bound. Last of them is to fit the new rear main oil seal into the retainer, however do not fit this retainer until the balance shafts are fitted.

Scrape off any Plastigage residue and lift the crankshaft out of the cylinder block. Apply lubricant to the bearing surfaces and lay the crankshaft back in place. Apply lubricant to the bearing insert faces and clean the engine block and bearing cap mating surfaces. Apply clean engine oil to all bolt threads and tighten the main bearing cap bolts to the specified torque.

If a dial indicator is unavailable, feeler gauges can be used to determine clearance.

Scrape off any Plastigage residue and lift the crankshaft out of the cylinder block. Apply lubricant to the bearing surfaces and lay the crankshaft back in place. Apply lubricant to the bearing insert faces and clean the engine block and bearing cap mating surfaces. Apply clean engine oil to all bolt threads and tighten the main bearing cap bolts to the specified torque.

Remove the bolts and lift off the main bearing caps, then compare the width of the crushed Plastigage to determine the main bearing oil clearance.

Remove the bolts and lift off the main bearing caps, then compare the width of the crushed Plastigage to determine the main bearing oil clearance.

Position the engine block with the bottom facing up and remove the main bearing caps. Clean the bearing surfaces and install new bearing inserts. Check the main bearing oil clearance using Plastigage. Apply clean engine oil to all bolt threads and tighten the bolts to the specified torque.

Mount a dial indicator and touch the end of the crankshaft. Pry the crankshaft to the rear and zero the dial indicator, then pry it to the front and check the reading.