Main Bearing Cap Bolts - TTY?

[BobQ]

A buddy of mine is helping me put a crank in my 6.2L. I told him to hold up on putting the crank in because I was going to try to get new main bearing cap bolts. Are the main bearing cap bolts on 6.2Ls torque-to-yield (one time use) bolts? I know the head bolts are TTY, but I hear conflicting stories as to whether the main bolts are or not. If they are, is GM the only place I can get new ones? The local GM dealer says that they can only locate 6 of the inner bolts and 1 of the outers (or vice versa). I called ARP and they don't make them for the 6.2L. Can I safely reuse the old main bolts?

Thanks.

[DmaxMaverick]

Good question. I don't think so, though. I don't know of anyone not reusing the bolts, including me. The bolts are NOT a problem. Never had one fail or see any signs of one letting up. I'm sure Robyn would agree. Studs would be another option, and maybe a better one, but I don't fix what ain't broke.

[BobQ]

Thanks.

I"ll go ahead and use the old bolts.

[Robyn]

The only bolts that are TTY on these engines are the Head bolts
The main bolts have never been an issue.

The only problems to watch for down under are the infamous main web cracks that can happen in the outer holes of the 3 center mains.

Even these cracks are not necessarily a death sentence.

If the cracks are within the upper 1/2 of the hole (and not at the register cut) the installation of a full torque insert (Lock and stitch) on the outer holes will nicely save the block.

Any bolt can fail or "stretch" if you find a main bolt that will not hold torque when you reach spec, then it may be suspect.

I have never seen any of these fail. Just torque them to spec and move on.

I have seen rod bolts get stretchy though.

If you find a rod bolt that the torque gets "creepy" on. replace the pair.

A creepy bolt will likely come back to haunt you.


Robyn