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Forum namePerformance/Engine
Topic subjectrod bearing question.
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=91854
91854, rod bearing question.
Posted by 97grnRS, Jul-27-05 06:14 AM
soon im gonna do a motor overhaul. new HG, rings ,valve seals and stuff. but if i buy new oem bearings for the rods can i just put them in or is there a chance they will spin eventually? i never spun a bearing or nothin but i dunno if the ones i have may have already worn a certain way or not. also when the bearings go in i know the top of the bearing gets assembly lube but does the bottom also ? the part that touches the rod surface? cause my haynes says no but that seems odd.
91857, RE: rod bearing question.
Posted by 96NTeclipse, Jul-27-05 06:47 AM
just go ahead and machine down the crank and replace with oversize bearings. If you replace the bearings, and the clearance is off, shit will hit the fan.
91858, RE: rod bearing question.
Posted by xcasbonx, Jul-27-05 06:48 AM
A word of advice, if ever over-hauling an engine...always replace the rod bearings. They might get a small amount of assembly lube but im not completely sure. Someone should be able to verify that one.


http://www.dsmregistry.com/detail.php?carid=1030
91861, RE: rod bearing question.
Posted by sike, Jul-27-05 06:52 AM
Check clearances of the new bearings with plastigauge from auto zone. You need a certain size, I can't recall which. I wouldn't have the crank turned if they check out ok. That is expensive and alot of work.
91862, RE: rod bearing question.
Posted by 96NTeclipse, Jul-27-05 07:08 AM
it's not really that expensive. Plus if your going as far as pulling the pistons out.. I would take a few more hours and pull the crank to have it machined. It just makes me feel a lot better when doing a rebuild.

As far as plastiguage goes, you should check the clearance if you have it machined or not. Your local machinist is human too, it can be off. And always check it across the bearing. if it deviates any across the journal, machine it.
91864, RE: rod bearing question.
Posted by 97grnRS, Jul-27-05 07:15 AM
i really dont wanna have it machined cause i need to do this whole rebuild in like 2 days since its my only car. but i dunno. i never had a bearing prob so maybe i can just leave them alone .
91871, RE: rod bearing question.
Posted by cougar694u, Jul-27-05 09:14 AM
The plastigauge is the way to check the clearence to see if you need to have the crank turned.

If it hasn't spun a bearing, and the old bearings look good, you're probably fine. When it spins the bearing, it tends to wear then and you'll have to have the crank turned. You could probably replace them with OEM spec bearings and be just fine.

As far as the assembly lube, the part that faces the rod does not turn, spin, or do anything. It stays stationary while the crank rotates inside of it. I usually put a little on it just to hold it to the rod or cap while assembling, but that's it, it's not a moving part that requires lubrication between the bearing & the rod.