speaking of stripped threads

[djw]

A long, long time ago I messed up the threads on one of the studs on the corner of the oil sump (where the plate mounts) on a mid 70's OIF. At the time and place I apparently did not want to do the job right so I tapped a larger thread and threaded in a 3/8 bolt in place of the 5/16 stud and moved on, and have been gentle with that bolt ever since. Not sure I did all that great of a tap job as it was done by hand in a hurry on my daily rider at the time.

I have never used a helicoil, recoil, keensert, or timesert before and I how would like to try and fix it up properly. The studs are readily available, even stainless.

I am curious about the insert process. I am reasonably handy but not all that experienced - forgive the newbie questions.

1. Are the taps for the inserts a standard size or a special thread or something? I don't think the helicoil or the timesert is (i.e. special tap) is but the keensert is supposed to be standard (not sure where to buy). I am wondering if the larger bolt I put in wayback when is likely to fit a standard insert and it would be ready to go for the 21-2025 5/16 18-24x1" stud. Might have to tap it out again (even larger?) to fit an insert, I think the minimum is 2 sizes larger (i.e. a 7/16 for a 5/16 coil and stud? Not sure how much I have to work with down there).

2. Looking at the stud description, is the pitch different on one end vs the other (i.e. the 18-24 part?). Which end goes into the frame? (I've since figured this out I believe the 5/16 18 course unc end is inserted and the 5/16 24 unf end is for the nut).

If anyone has replaced studs on the sump like this please pass along any tips. I'd like to fix it properly but not make the problem worse and turn it into a major dilemma just trying to make it right.

Thanks.

[Mecchanica]

Yes, the coarse thread installs into the frame. The tap is a special one for that application. Make sure to install an insert no longer than the thickness of the frame plate. Solid inserts are usually better for thinner applications like this. You would tap it out even larger, probably 7/16", and then run the insert in with a screwdriver and red or green loctite on the threads. It's slotted for that. For good measure, after the loctite sets up, run a tap through the threads to make sure that the stud will easily thread into it, and use loctite on the stud, too.
You can also silver solder or braze the stud into place.

[sgreimer]

I am concerned that I have weak threads as well on the studs for the oil sump plate. I am glad to hear that those studs come out and can be replaced. Hopefully I won't have to go this route though. Will take a close look on the next oil change.

[pookybear]

Originally Posted by Mecchanica

Yes, the coarse thread installs into the frame. The tap is a special one for that application. Make sure to install an insert no longer than the thickness of the frame plate. Solid inserts are usually better for thinner applications like this. You would tap it out even larger, probably 7/16", and then run the insert in with a screwdriver and red or green loctite on the threads. It's slotted for that. For good measure, after the loctite sets up, run a tap through the threads to make sure that the stud will easily thread into it, and use loctite on the stud, too.
You can also silver solder or braze the stud into place.

Mecchanica,

Good answer, but use the Green loctite on the insert, it is also
called sleeve retainer. And save the Red loctite for the stud.

Pookybear