Stripped Tail Shaft Housing Thread

[KCbelvedere]

So I finally got to final assembly of the 727 and as I was bolting the tail shaft housing down the last bolt just kept spinning on me. Pictures are attached. This is a hole that goes all the way through the case. What are my options? Will a helicoil work or do I need to dump this housing?

 

[Mike67]

Helicoil

 

[Geetex]

I personally don't like Helicoils as I've seen too many of them pullout, especially in aluminum. I prefer the locking threaded inserts as shown in this link, but you have to have enough material around the stripped hole to work with. Click on the link at the top of the page that says "how to install key locking inserts" and you'll see how they work.
https://www.mcmaster.com/threaded-inserts/key-locking-inserts-with-installation-tool/
The kit is kind of expensive but worth it if you do a lot of these repairs. I'm sure in this case it's a one time repair for you, so to save a few bucks, you can just buy a pack of inserts and carefully set the locking pins with a hammer, I've done it before, just be careful so you don't break the locking pins off. Just another possibility, hope it helps and good luck with your trans.

 

[NoCar2023]

Used these for years in the dealer.
https://www.amazon.com/TIME-SERT-8-...ocphy=9031206&hvtargid=pla-570483735993&psc=1

 

[coloradodave]

Helicoil. I've used them for many, many years. Never had one pull out. Installation instructions must be followed exactly and correct torque value used.

 

[Dipstick]

Room for a thin nut inside the case?

 

[1967coronet]

Tap out to the next size up.

 

[dvw]

I build many transmissions. Heli-Coil trans threads all the time. These parts are 50 years old. Many of them have been apart many times. Never had a Heli-Coil pull out, EVER. Heli-Coil it and rest assured its repaired. How could a Heli-Coil that was installed properly pull out? I'd like to see it. My racecar trans has a few in it right now. There's even one in the cylinder head. Time-Serts have there place. But are unnecessary in this application.
Doug