GM 14085481 Crankshaft

The following are the general steps to follow, Start by withdrawing the engine of the car and placing on a stable stand. For the L4 engines, remove crankshaft pulley and hub assembly, for V6 engines, remove crankshaft pulley assembly, torsional damper assembly. Subsequently, remove the oil pan, and the oil pump assembly. L4 engines timing gear cover should be removed; L4 V6 engines water pump, crankcase front cover, camshaft sprocket and the timing chain should also be removed. Continue and take out the pistons and the connecting rods from the crankshaft and finally the flywheel. See to it that all the main bearing caps have corresponding positions of the engine block if not you can dent them to help in identification. Remove the main bearing caps, as well as the corresponding bearings that are fixed to the crankshaft, and put all of them on a workbench in the same sequence as they are installed in the engine block. Carefully raise the crankshaft out of the engine block, using care to prevent any scratching of the rod bearing bores, as you would during installation; then extract the rear main oil seal. Last but not the least; remove the main bearings and the main bearing cap from the block maintaining their positions respectively, further depending on the crankshaft configuration; the gear or sprocket might be pulled out using a special tool known as puller.

The following are the general steps to follow, Start by withdrawing the engine of the car and placing on a stable stand. For the L4 engines, remove crankshaft pulley and hub assembly, for V6 engines, remove crankshaft pulley assembly, torsional damper assembly. Subsequently, remove the oil pan, and the oil pump assembly. L4 engines timing gear cover should be removed; L4 V6 engines water pump, crankcase front cover, camshaft sprocket and the timing chain should also be removed. Continue and take out the pistons and the connecting rods from the crankshaft and finally the flywheel. See to it that all the main bearing caps have corresponding positions of the engine block if not you can dent them to help in identification. Remove the main bearing caps, as well as the corresponding bearings that are fixed to the crankshaft, and put all of them on a workbench in the same sequence as they are installed in the engine block. Carefully raise the crankshaft out of the engine block, using care to prevent any scratching of the rod bearing bores, as you would during installation; then extract the rear main oil seal. Last but not the least; remove the main bearings and the main bearing cap from the block maintaining their positions respectively, further depending on the crankshaft configuration; the gear or sprocket might be pulled out using a special tool known as puller.

Stamping the cylinder number on the connecting rod bolt bosses and caps is important for identification purposes.

Measure the connecting rod side clearance with a feeler gauge between the connecting rod caps, and if it falls outside the specified tolerance, replace the rod assembly.

For a Quad-4 engine, check the oil pump drive gear for wear and damage. If replacement is required, take the crankshaft to a dealer service department or an automotive machine shop for removal and installation of the new gear.

Clean the crankshaft with solvent and dry it thoroughly, ensuring to clean the oil holes with a stiff brush and flush them with solvent.

Undersize bearings are available to match the recommended regrind diameter, typically supplied by your GM dealer with the reconditioned crankshaft.

Before removing the crankshaft, check the endplay by mounting a dial indicator with the stem aligned with the crankshaft and touching one of the crank throws.

Have the crankshaft reground by an automotive machine shop, ensuring to use the correct undersize bearing inserts if reconditioning is necessary.

Unbolt the main bearing caps and carefully lift each cap along with its corresponding bearing off the crankshaft, placing them on a workspace numbered to correspond with their positions in the engine block.

Loosen the main bearing cap bolts a quarter turn at a time until they can be removed by hand, ensuring the caps are marked for their proper locations, typically numbered from front to rear.

Remove the main bearing cap bolts and lift out the caps, laying them out in order for correct reinstallation.