Lecture me on thread inserts

[Pranav]

The 4th gen torque arms are held to the T56 transmissions with three bolts. Two of them pass through the transmission and are held on by nuts on the other side, while the third threads into a blind hole in the aluminum tail housing.

It is a common occurence for this 3rd bolt to back out, eventually falling out, causing the outer torque arm bushing bracket to fall off the car and turn the torque arm into a massive swinging hammer under the car. A common solution to this problem is to ditch the bolt, and throw in a stud with double nuts.

Long story short I lost a bolt and now the (already) beat up hole seems to have only a few good threads left.

It's an M10x1.5 hole, looks like most of the inserts will have me drilling and tapping out a hole as big as M16?

The attached pics show what I'm working with.

Which is the better option, doing an insert, or just going up one size to M12? If insert is the better option, which brand/kind should I go with? I was thinking the following:

http://www.amazon.com/E-Z-External-Threadsly-Threaded-Stainless/dp/B00DCFIASE/ref=sr_1_4?ie=UTF8&qid=1390530322&sr=8-4&keywords=threaded+insert+m10x1.5#productDescriptio n

[RichardP]

Given the limited outer diameter you have to work with, I'd be more inclined to go with a Heilcoil. It is just a coiled wire that is specifically designed to fix what you have. The link you provided seems to be more like a Keensert. It is an actual machined part with inner and outer threads. In theory, it is a bit stronger but you have to have sufficient parent metal to work with.

http://www.acmeindustrial.com/images/ACME-insert-comparison.gif


Richard P.

[Fbody383]

I helicoiled mine; not sure when i'll see the toolbox again but I can get you what I used. I want to say I went back "stock." Then I cut the head off a bolt to make a stud, locktighted that into the trans, and locktight double nutted (vs. nylock nut) the bracket on.

I'll let you know what size I used when I can.

[Pranav]

Dave were you able to do it with the trans still in the car? I've dropped the trans mount and got the back end of the trans to hang pretty low, but I've got poly engine mounts so there's still some trans tunnel in the way.

How well are helicoils supposed to take multiple cycles of tightening/loosening? I had a bad experience with intake manifold bolt holes in my heads being helicoiled....

[RichardP]

How well are helicoils supposed to take multiple cycles of tightening/loosening? I had a bad experience with intake manifold bolt holes in my heads being helicoiled....

That's the point of using a stud. Use red loctite to install the stud and the hole won't care about cycles.

Richard P.

[Fbody383]

Dave were you able to do it with the trans still in the car? I didn't have to try, I did it when the trans was out... unfortunately it gets to come out again. You might be able to loosen up the K-member bolts a little too to get some room if you don't want to pull the trans.

Support everything and be careful.

[ShadowBolt]

You don't have to use metric.

JJ

[GlennCMC70]

Just drop the tailhousing off.

[Pranav]

Just drain the fluid, undo those bolts that go all the way around, and punch out some pin in the shifter hole?

[Fbody383]

http://www.fordmuscle.com/archives/2002/09/transmissions/LD56-0610-0199.pdf

[Pranav]

Looks easy. Any risk of bearings or gears and crap falling out, nothing I have to shim or measure when I put the housing back on?