Jeep 4781071AB CRANKSHFT

You can Select Your Vehicle to check if 4781071AB fits your vehicle.

The crankshaft can only be removed with the engine being pulled out of the car provided several other parts have been removed; these are the flywheel, crankshaft pulley, timing belt/chain, oil pan, oil pump body, oil filter, and the piston/connecting rods. Before spiking out the crank shaft, put the dial indicator in contact with the crank shaft to determine the crank shaft end play. With the crankshaft pushed to the rear, slightly rotate the indicator tip until the pointer reads zero, then push the crankshaft to the front, read the indicator which should be in the range of 0.003 to 0.010 inch. A dial indicator may not be available and the use of feeler gauge is acceptable in order to get the clearance. Unthread the bedplate or main bearing cap screws progressively and then gently use a hammer to knock it off if you cannot lift it off by hand but be careful not to drop the bearing inserts. Slowly raise it right up, preferably with help, and replace the beds or mains with the arrow pointing towards the front of the engine. For installation say the engine block and the crank shaft have to be clean and have to be inspected. Place the block in an inverted manner in the hole, and if there are any ready-made bearing inserts present they must be withdrawn and the area scrubbed. New upper main bearing inserts should be fitted and correct position of oil holes for them, the correct journal position of the thrust washer. Scrape and deglaze the crankshaft and bearing surfaces then set the crankshaft in position. Feel the main bearing oil clearance with the help of Plastigage and do not take apart the assembly. After this tighten the bolts as per the sequence shown above and then take out the assembly in order to check the width of the Plastigage for the clearance. If it is necessary remove bearing inserts to have correct clearance. Remove any of the Plastigage deposits and put a new thin layer of the grease on the bearing surfaces and replace the crankshaft. Check that the engine block is clean and apply anaerobic sealant, if necessary. Place the principal bearing assembly in correct position and tighten the bolts in sequence. Ensure that the crankshaft end play is correct; turn the crankshaft clockwise and anti clockwise and ensure it does not bind. Last but not the least, fit the new rear main oil seal.

Install the main bearing assembly, ensuring proper alignment, and tighten the bolts in the specified order.

If the endplay exceeds the specified value, inspect the crankshaft thrust surfaces for wear. If no wear is found, replacing the main bearings should resolve the issue.

Check for uneven wear, scoring, pits, and cracks.

If the original bearing inserts are still in place, they should be removed from the block and caps, and the bearing surfaces should be wiped with a clean, lint-free cloth to keep them spotless.