Threading JB Weld
 

I have a shift knob whose thread doesn't match the shift lever I want to put it on. Ive tried making an adapter with no success. I'm considering using JB weld instead.

Would I be better off:

Filling the threaded hole in the shift knob with JB weld then drilling and tapping

-or-

Coating a bolt with a release agent and casting it into the JB weld to create a thread


Thoughts? Other ideas?

I bought a cue ball shift knob that came with 3 or 4 threaded bushings/adapters. Maybe one of those would work or you could make similar by threading the ID/OD of a nipple. Hard to say without knowing size and threads.

What's the thread size?

You might be able to find a suitable thread insert at McMaster Carr and install it in the shift knob.

I have filled holes and drilled/tapped JB Weld on non-critical stuff; it seems to hold OK, but won't take a lot of torque.

I've searched high and low for a reducing bushing; I've even tried to make one. The thread in the knob is 3/8-24; the thread on the shifter is M8x1.25. I think there's just not enough wall thickness between 8mm and 3/8 to pull it off. Oh by the way, it needs to be something that won't corrode, like stainless. There are adapters, but they lengthen the shifter which is not ideal.

Have a look at using a time-sert ?

Couple of ideas below.

Got enough material in the original thread to drill out to 7/16?:

https://www.mcmaster.com/threaded-inserts/thread-size~m8/tapping-inserts-for-soft-metal/

Able to tap the existing hole bigger?:

https://www.mcmaster.com/threaded-inserts/thread-size~m8/18-8-stainless-steel-easy-to-install-thread-locking-inserts/

https://www.mcmaster.com/threaded-inserts/thread-size~m8/18-8-stainless-steel-key-locking-inserts/

If you want to go ahead with JB Weld, I would start with flushing out the existing tapped hole with carb cleaner and then follow with alcohol. Let it dry. Fill the entire hole with JB Weld and let is sit for 24 hours minimum. Then drill/tap.

Are you sure it's a 3/8-24? Most SAE threaded knobs are 3/8-16.

Here's what I did to adapt my Wevo tall shift knob to the Hurst shifter stick with the custom shifter I've got. I drilled out the inside of the knob just slightly. I then used a 3/8-16 nut which I ground down on the outside so it was a tight enough fit into the Wevo so that I could tap it in with a hammer. I was going to go back at some point and JB Weld it in but it's never moved so I didn't bother.

http://forums.pelicanparts.com/uploa...1622467532.JPG

This is what I recommend

https://www.muggyweld.com/products/

https://www.youtube.com/watch?v=3pVS3Jttozk