Oldsmobile 10243070 Engine Crankshaft

The endplay should be checked before removing the crankshaft. With the stem aligned with the crankshaft, a dial indicator needs to be set up so that it touches one of the throw arms. After pushing the crankshaft completely backward, zero the dial indicator. Then pry the crankshaft as far forward as possible and read on dial indicator. This movement determines how much endplay is. If it exceeds what's prescribed, examine the thrust surfaces on the crankshafts for wear. If no evidence of wear exists, new main bearings would correct this clearance problem. In case you do not have a dial indicator, you can use feeler gauges instead. When prying or pushing on it with care, make sure to move the crankshaft until it reaches at extreme front of engine block. The clearance between the front face of thrust main bearing and the crankshaft should be measured using feeler gauges. Do these bearing caps have any marks indicating their locations. It is from front to rear numbering them consecutively. If there are no such marks they could be numbered by number stamping dies or even center punch in case they are not cast-in top of the main bearing caps showing any arrow out pointing to front side of engine block. One-quarter turn at a time each should be loosened every one of main bearing cap bolts until they can easily be taken out by plain hand. Thus each cap should then be carefully tapped using soft-faced hammer and separated from engine block when necessary; bolts could remove caps if needed. Well, as long as you don't lose them along with corresponding bearing caps you don't need to worry about dropping those inserts. Upon lifting it up cautiously from engine block assisted by someone else due its weighty nature, the best way could involve having an assistant around in order for ease lifting of this entire crankshaft. The respective locations where each cap belongs can easily guided by looking at them while holding bearing inserts within engine block and main bearing caps are returned by tightening their bolts with fingers only.

Crankshaft and main bearings should be removed only with the engine taken out of the car and then the engine must be fully dismantled. It is necessary to insure ourselves that the original numbers or letters on the 5 main bearing caps of the engine block are visible and clear; if not, small dents may be made according to the same combinations as were the connecting rods and caps to guarantee that the main bearing caps are put on their proper places. Subsequently, each of the main bearing cap together with its bearing should be removed by lifting it off the crankshaft and all the main bearing caps and bearings must be arranged on another workspace arranged in serial fashion with relation to the engine block. The crankshaft should then be carefully lifted off the engine block in order not to cause any damage. The oil seal consists of two halves which have to be taken out, next, the main bearings have to be taken out from both the cylinder block and the caps, but it is necessary to sort them according to their positions. Last but not least, called 'Crankshaft gear removal tool or Puller,' the gear at the front of the crankshaft can be effortlessly removed.

Ensure the engine block and crankshaft have been completely cleaned, inspected and repaired or reconditioned before starting to reassemble the engine. Put the engine bottom up and remove the main bearing cap bolts, placing them in an orderly manner for proper installation. If there are still old bearing inserts at their places, remove them from both the block and main bearing caps. Clean the main bearing surfaces of the block and caps cautiously; keep them free from any debris. After that, clean the back sides of new main bearing inserts. Place one bearing half in each block's main bearing saddle first ensuring that tab on insert aligns with recess and oil hole in block matches insert. Do not hammer or damage faces of bearings during this process neither use any lubricant. The flanged thrust bearing must be installed in the rear cap and saddle. Clean when you are done with cleaning all bearing faces and crankshaft main bearing journals making sure to check and clean oil holes of crankshaft as well.Carefully position it in place within mains with assistance from someone else if required.Before installing crankshaft permanently, it is important to check main bearing oil clearance.Cut several small pieces of Plastigage into appropriate lengths; place these across each crankshaft's main journal.Put down all main cap bolts so that they face forwards towards front of engine.Tighten the caps' bolts following a careful sequence without rotating shaft.Remove bolts then caps making sure that Plastigage has not been disturbed.Compare widths of squashed Plastigage on each journal against scale on Plastigage envelope to find out what is your oil clearance.Correct any variations as needed afterwards scrape off all paper materials from major journal surfaces and faces without causing any other harm.The last step in putting crankshaft in place is applying thin even layer of clean moly-base grease or engine assembly lube onto surfaces below the bearings within block taking care to coat thrust faces properly.Put back the crankshaft into place in block again clean the surfaces of caps' bearings, apply lubrication and put on caps having arrows facing forward.Slightly tighten cap bolts in a specific sequence with reference to specified torque levels.Move handle to check if it is binding and inspect end play using feeler gauge or dial indicator for any runout.Finally, depending on engine type and model year, install such components as pilot bearing or crankshaft rear oil seal and housing.

Clean the lower bearing inserts and install them in the main bearing cap assembly, ensuring proper fit without damage.

Clean the crankshaft with solvent and dry it with compressed air, if available.

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.

By measuring at various points around the journal's circumference, you can determine if the journal is worn out-of-round, and take measurements at each end of the journal, near the crank throw, to check for taper.

The flanged thrust bearing must be installed in the appropriate cap and saddle for V6 and V8 engines.

Loosen the main bearing cap bolts and remove the caps. Lift the crankshaft out of the engine, being careful due to its weight.

If a dial indicator is unavailable, use feeler gauges by prying the crankshaft to the front and slipping the gauges between the crankshaft and the thrust main bearing to measure clearance.