connecting rods

[Phoenix0249]

Hey, I have a bad main bearing on the crankshaft and it wore a good bit off of the crank, which leads me to believe it did the same to the connecting rod. Is it safe to replace just one connecting rod or should they all be replaced? Thanks

[4kQuad]

There should be a bearing between the rod and the crank. If the bearing didn't wear through, the rod "should" be ok.

So is there anything left of the bearing??

[Phoenix0249]

The bearing didn't wear through completely, just off of the surface. But the little tongs on both pieces or the bearing are completely missing, so i'm not sure if that means it wore down the connecting rod or not.

[rixGAphx]

Take the old con rod to NAPA when you get the new bearings, and check for fit. Actually, you should be able to see if there's any damage to the rod.

Yeah, you can replace a single rod. Just make sure the new rod is within about 5 grams (1/6 oz) of weight of the old rod.

High-performance engines are buillt with matching con rods, 'balanced' to within 1 gram of each other, so that the reciprocating masses (rod/piston/wrist pin/rings) are nearly identical.

Detroit engines, even the relatively-sophisticated 2.4, are built to less-stringent tolerances, so matching weights within 5 grams should be ok.

BUT, replace all main and rod bearings, even if you only replace one rod.
And, since that rod has to come out of the bore to change the rod, you *should* install new rings on its piston. Therefore, install matching new rings on the other pistons, and have the cylinders honed while you're at it.
If the cylinders need boring instead of just honing, then you'll need new pistons. Might as well get three more new rods while you're at it, since the old rods would have to be pressed into the new pistons anyhow.
Do the job like a performance engine builder, and match the reciprocating weights of the new sets of rods/pistons.

Good luck.
-Rick