helicoil/helicoil+JB/JB/threadsert/JB+threadsert?

[TurboSE]

**I apologize in advance if any of my terminology is incorrect)

I'm putting the finishing touches on my RB build and I noticed one of the bell housing bolt holes (in the block) is a helicoil. I noticed because it is significantly larger than the other holes and it seems to be "uncoiling." It is the upper bolt on the exhaust side if that matters. Upon screwing a bolt in, it seems to be unsquare, not significantly, but it's noticeable. My machine shop didn't do this (they'd have told/charged me), so it must be from the original owner.

I've done some reading and I've found that helicoil isn't the only way to rethread a hole. Threadserts look great, but I really don't want to drill out any more of the cast.

What would you guys recommend?

Cut off the uncoiled thread (probably 2 threads) and use it as-is?
Just reinstall a new helicoil?
JB weld, drill and tap a new, square helicoil(would be nice to get back to stock size)?
Fill with JB and tap(Sounds like a weak solution, but I had to ask)?
Tap the hole and use a threadsert (stronger than a helicoil)?
JB weld, drill and tap for a square threadsert?


I'm up for any and all suggestions, just looks like enough material has been removed, I'd like to avoid removing more.

[scotto]

Just put in a new helicoil and use some red (strongest) Loc-Tite thread locker. That won't be an issue and will probably hold better than JB Weld.

[jr_ss]

Don't use red, blue is sufficient. He'll need to get that bolt out some day.

[fullthrottle]

Don't use red, blue is sufficient. He'll need to get that bolt out some day.

red loctite on the outside threads of the helicoil. some people shouldnt be allowed to post about technical things.

Sent from my SGH-T769 using Tapatalk 2

[dawagarage]

red thread locker is for permanent installation parts and requires heat/special tools to remove.
blue, medium strength is for removable parts that benefit from a thread locker

so yes you would want the red on the inside outer dimensions of your preferred insert.

have you considered timeserts?
http://www.timesert.com/images/index/image003.gif (http://www.timesert.com/html/install.html#A)
++ TIME-SERT Threaded inserts for stripped threads, threaded inserts, thread repair stripped sparkplug's, Ford sparkplug blowouts, threaded inserts threaded, repair stripped threads, stripped threads, inserts threaded inserts, Ford spark plug repair, (http://www.timesert.com/)

[jr_ss]

I was assuming the gentleman above was talking about the bolt once the new Helicoil has been inserted. Wasnt considering putting red on the Helicoil itself. Typically they have a tang you break off to prevent them from backing out at the bottom.

[scotto]

Thank you for calling me a gentleman, its much better than what I'm called at work :)
And yes, I was talking about putting the threadlocker on the helicoil itself, not the trans bolt for the O.P.

[TurboSE]

I never thought about thread locker on the outside of the helicoil. Thats's good info. I have/am considering Timeserts, for some reason I was calling them threadserts. I like the concept...do you think they're a better idea than Helicoil? The hole is already tapped for a helicoil, do you think I could find a Timesert with the same threading to avoid removing any more material?

[TurboSE]

Helicoil tap chart , helicoil tapping chart , helicoil tap size, helicoil tapping size, helicoil tapping data , helicoil tap data , helicoil , heli-coil , helicoils , helicoil tapping depth (http://www.noblefix.com/helicoil/HeliCoil-Tapping-Chart.html)


From this page, it looks like the sizes are pretty similar.

[TurboSE]

Ok, so I ran into a new issue...it seems that the hole is tapped to 1/2-20sti (special tap used by helicoil and Time Sert)...and that either helicoil or Time Serts will only restore the hole to 1/2-20...which is too big for the bell housing bolt holes, any ideas?

I am considering having a stud machined that is 1/2-20 on the block end and M8x1.25 through the bell housing.

Or a bushing that is 1/2-20 on the outside and M8x1.25 on the inside.

Your thoughts?

[TurboSE]

I think I'm gonna go this route. I'll need to retap the hole to course threads but it'll get me back to the stock M8x1.25 threads.

Industrial Style - Single Size Kits Keylocking Threaded Inserts Metric Internal / Inch External (http://www.acmeindustrial.com/SSKits_MI_IE.html)

[dawagarage]

i think 'timesert' is just the name for the product by that specific company.
the general term might be threadsert, threaded insert, or reducer, or a few other names.

whoever has it cheaper, go that route. i didnt know timesert used/required a special tap and all that. there are reducers out there that will reduce it from a regular metric hole (od) IE M12x1.50 (od) reduced to M8x1.25.

[dawagarage]

call around your local hardware stores and ask around.
youll have to redrill/tap that hole if you go that route...

[TurboSE]

after further searching, an sti tap it's supposed to be significantly than a standard trap of the "same size" (ie a 1/2-20 bolt shouldn't thread properly, if at all...and it does.) I'm guessing whoever did the repair just used a standard tap, and that's why the Helicoil didn't take.

I looked at the metric-metric reducers (M12x1.75-M8x 1.25) and it turns out I'll actually get more thread from going 1/2x13...about 7/320"...but it's something.