65vettish

I was mounting a new backup light switch on my 65 Muncie and discovered one of the bolt holes is stripped at the cover plate where the switch bracket mounts. It looks like someone tried to repair the hole previously as what appears to be a thread insert came out with the bolt. What's the best way to repair this hole with the transmission in the frame? Helicoil, timesert??? Note, the car is a 66 Chevelle with the body off so access to the tranny is not a problem. I just don't want to take the tranny out if I don't have to. Thanks for your help.

wmf62

other than an oversize hole and retapping, the only other way I know would be a helicoil. it puzzles me as to why the present threaded insert cam out with the bolt unless the threads for it are stripped....

if the threads are not buggered-up too bad, maybe the insert can be JB welded back in and then the threads cleaned out with the right size tap after the epoxy has set up.

Bill

59BlueSilver

I repaired my tranny with E-Z Lock threaded inserts.

66jack

But i hope you meant "chase the threads"...

wmf62

yep I did...

Bill

Chuck72

Your choices, other than welding the hole up, are Heli-coil, Time-sert, or Big-sert, depending on the condition of the hole.

https://www.amazon.com/BIG-SERT-Time...RB4T1JPSRRKZEY

People use bolts that are too long for the blind hole, the bolts bottom out because they don't have, 'Wrench feel.' They crank down, the bolt bottoms out, the soft aluminum case threads yield. JMO

65vettish

Thanks for the responses guys. This is my first time fooling with a transmission other than taking it out and installing it but not my first repairing a stripped bolt hole. If I repair the hole by tapping it w/o removing the transmission, should I be concerned about shavings falling into the case? What's a good way to avoid that?

66jack

This is what i would try...I would put some grease on the 'chase/tap' and on the backside to collect 'anything' that might contaminate the insides of trans...

Hope this makes sense...

I 'think', if its accessible from the inside...where you can put some heavy grease on the hole 'and' when you chase the threads use some grease on it...make sure the grease 'blob' doesnt fall into case...so you might want to back that up with your finger so you know/feel it start to come through and wipe off that one.... back it off and reapply some grease...using you finger you should be able to feel if any 'sharp' shavings are on the inside...

Good luck

My 2cents...

Avispa

Heli-coil. My Muncie is full of em. Main bearing retainer bolt holes, 3 side cover bolt holes, one tailshaft bolt hole and both rear mount pad bolt holes. Not a hint of trouble in 22 years.

65vettish

Excellent suggestion! I've done that years ago but honestly didn't even think about it for this repair. The older I get the less I remember...it happens.