Rod Bearings Questions

[d-man-sho]

Hey All,
Intead of using plastigage on every bearing when i install them to make sure the parts gave me the right ones, can i just have them bust out the mike and measure them when i pick them up?

Removing the rear main seal carrier gasket disturbs the oil pan gaskets, so I'm assuming i should install the new carrier gasket(im doing the clutch also) before the new oil pan ones right?

Thanks,

-David

 

[DHMag]

youre not measuring for the correct bearing, so to speak. youre using the plastigage to insure the crank has not worn excessively. if the gage is out of factory spec, undersized bearings are required.

 

[d-man-sho]

Oh I thought that unless a rod was spun, that it didnt need to be measured for wear because there isnt much that can be done if they are out of spec a little, and that the new bearings are going to be tighter than the old ones anyway. Thats why i thought they just needed to be measured so you know you recieve the correct parts from the countermen.

 

[shojuan]

Read the markings on each bearing to make sure you got the right parts from the counterman.

I think in the absence of a bearing failure the crank will never wear enough where undersized bearings will fit better than standard sized. You fit undersized bearings if you have the crank machined and you machine the crank if you have a bearing failure.

I think it's pretty sound reasoning that new standard bearings are going to fit an undamaged crank better than the worn bearings that are in there. Plus the rod bolts are only good for a couple of torquings. I don't think anybody has ever claimed that replacing rod bolts is fun while the engine is in the car. Save a torque cycle on the bolts and don't measure the clearances. Just verify that you have the correct bearings by looking at the markings on the new bearing.

 

[d-man-sho]

Thanks, i didnt know they were marked

Do i need to replace the rod bolts? This is the first ive heard of them after searching.

-David

 

[shojuan]

Do i need to replace the rod bolts? This is the first ive heard of them after searching.

The first time the rod bearings get replaced? No. Especially if you don't plastigage the crank to bearing clearances. I think 3rd or 4th time they get torqued down they should be replaced. Others here know for sure. Remember, they were torqued down once at the factory.