Helicoils in a Bellhousing

So.....as my restoration saga continues, I have found problems with the Bellhousing that I purchased on ebay; ie. it has some stripped bolt-holes. The seller will refund my money if I return it; which is good. However, that delays the reassembly of the drive-train further and I'm not guaranteed a good working Bellhousing no matter where it comes from I'm afraid. I've heard of people using Helicoils in repairing stripped bolt connections, but I have no experience whatsoever about these. I assume a large drill press is best so they can be installed exactly where and aligned perfectly....machine shop in other words.

Thoughts?

-Dave

I'm assuming the stripped holes are the transmission mounting? I wouldn't have any problem using Helicoils as a repair procedure. If you are still hesitant, the following item is also a repair procedure for a stripped internal thread. The only drawback is that they require a larger hole than a Helicoil.

https://www.fastenal.com/products/details/11138991;jsessionid=B1A6A87B0E6C987316B23A8403AAE7F9.fcomjvm04?r=~|categoryl1:"600000 Fasteners"|~ ~|categoryl2:"600186 Thread Repair"|~ ~|categoryl3:"600189 Threaded Inserts"|~

As to drilling them, any reasonable sized drill press should give you acceptable accuracy if you don't do something stupid like too rapid feed or trying to go to final size in one step.

I think helicoils are an approved repair for many things. I've used them and seen them used and never seen a failure. They would be better than original in an aluminum bell housing. The initial outlay for the tap and inserts might be a bit pricey though. If the thread is deep sometimes you can get two inserts in end to end.

helicoils are stronger than original

Helicoils are often used in new aluminium parts because they are stronger and more durable than threading directly into the aluminium. I wouldn't hesitate to use them as a repair in this situation.