Repairing Stripped Muncie side cover bolt holes

[Bill L.]

Re: Repairing Stripped Muncie side cover bolt holes

Here is a Helicoil tip that I have used, and still use, MANY times------------------on ALUMINUM, repeat, ALUMINUM parts.
ALUMINUM, NOT STEEL/IRON!

Rather that try to drill a straight hole where the threads are stripped in an alum part, insert the bolt and continue to finish stripping out the threads completely. Then insert the Helicoil tap and slowly turn it using plenty of lubricant. What remains of the original stripped out threads will "guide" the Helicoil tap straight and true into the hole. I do this ONLY on alum parts because it is a much softer metal than iron/steel, and the tap can easily follow and cut new threads in the alum. It just makes it TOOOOOOOOOOOOOOO EASY!

Now this may be something I am ready to try. Great idea Now I have to hope that the other 5 will have one more good 20 ft lb. torque left on those threads.

Hope someone else benefits from this advise too


Bill

[Timothy B.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill,

I remember using the method Tom suggested on the stripped oil pan plug threads on my 67 corvette. There was no nut plate, just a large nut and I went slow using the heli-coil tap to clean it up then install the 1/2" heli-coil. The nut was stripped pretty bad but what was left of the stripped threads guided the tap, I never drilled the hole.

The pan was off the engine and the repair took 10 minutes, I remember thinking how easy and fast this repair went and there are no problems with leaks.

[Dennis C.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill,

the use of a tap aligner will assist with tapping the hole square to the work.

Take a look at this:

http://www.mcmaster.com/#tap-guides/=q14o1l

Dennis

[Bill L.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill,

the use of a tap aligner will assist with tapping the hole square to the work.

Take a look at this:

http://www.mcmaster.com/#tap-guides/=q14o1l

Dennis

Lots of great info.

Thank you,


Bill

[John D.]

Re: Repairing Stripped Muncie side cover bolt holes

I agree with Dick Whittington. Except for the 60 year thing. Only been using heli's for about 50 years or so.
Use the proper Loctite. The red Loctite works good. I will have to try the PST.
The average FI restoration takes 4 to 5 helicoil's. Hardest ones to install are for the intake manifold aka base plate. They have to be dead nuts or big trouble.
If you are installing a heli-coil on a thin wall area that's trouble in the making.
Don't forget to remove the tang at the end of the heli-coil. JD

[Bill L.]

Re: Repairing Stripped Muncie side cover bolt holes

I agree with Dick Whittington. Except for the 60 year thing. Only been using heli's for about 50 years or so.
Use the proper Loctite. The red Loctite works good. I will have to try the PST.
The average FI restoration takes 4 to 5 helicoil's. Hardest ones to install are for the intake manifold aka base plate. They have to be dead nuts or big trouble.
If you are installing a heli-coil on a thin wall area that's trouble in the making.
Don't forget to remove the tang at the end of the heli-coil. JD

I thought the tang was there to help insert the coil.

Based on removing the tang I am thinking you just screw it in until flush?

Thanks, Bill

[John D.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill, Yes the tang is there just to installo the heli-coil. Now if it's a blind hole and the heli coil is bottoming out then one could leave the tang. But other than that you must remove it. I have a special spring loaded tang remover for every size on the FI's. But you really don't need this tool. jUst use the proper size punch.

Forget using teflon tape, paste and other "stuff" on a thread. Put in a new thread no matter what it takes.
Heli-coil kits are expensive. One might consider just having the local machine shop do the job.

[Domenic T.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill,
You have the right solution now, but sometimes you can measure the depth of the hole and put a longer bolt in it to get a seal. Can't tighten it like the others but it can work till your ready to do it or if it has to come down for something else.
When I do that I mark the bolt with yellow marker to let me know something is not right. I thought I would remember that I needed a heli coil and assembled a case only to find that I had a partually stripped out hole. Memory wasn't so good a few years after I used the longer bolt, now I mark them.

DOM

[Bill L.]

Re: Repairing Stripped Muncie side cover bolt holes

Thank you for all the assistance. I used the method as suggested by John D. It looks like the operation was a success. I put the side cover back on and had no problem getting them tightened and torqued.

Now I have to hope and pray the other holes that would torque to 20 ft. lbs. will still torque without stripping.

Bill

[Dick W.]

Re: Repairing Stripped Muncie side cover bolt holes

Bill, Yes the tang is there just to installo the heli-coil. Now if it's a blind hole and the heli coil is bottoming out then one could leave the tang. But other than that you must remove it. I have a special spring loaded tang remover for every size on the FI's. But you really don't need this tool. jUst use the proper size punch.

Forget using teflon tape, paste and other "stuff" on a thread. Put in a new thread no matter what it takes.
Heli-coil kits are expensive. One might consider just having the local machine shop do the job.

I thought you were just being your usual"cheap" self when you were talking about expensive until I looked up the price. Geeze, my set goes from 8-32 to 1-14. Wow! They have gone out of sight. Almost $150. 00 for the 1" and over $40 for the small kits.