I've got an old Hurst T handle shift knob. It was in a Challenger I bought back in the mid 90's and it was old back then. I assume it is a 70s or 80s part. Does anyone know what thread is cut into these? I know they were sold with adapters so they could be mounted on many different shifters. I don't have any adapters and want to use it on a project I'm making. I looked up a new one on the Summit Racing website and those are listed as being 1/2x20 thread. The one I have is larger. Putting a tape across the hole it measures 11/16". I can take it to the hardware store and try to match up something as long as it's not some weird thread.

So did you measure the hole between the threads, or were you guestimating the outside edge of the threads? I suspect you measured the hole, which would probably make it a 3/4" thread. Then its either fine thread, or course thread, but its probably fine thread. The next smaller standard bolt size would be a 5/8" either in course or fine thread. An 11/16 is an odd size.

Take the shift handle with you when you go to a real hardware store and check to see if a 3/4" bolt (or a 5/8" bolt) will screw into it, you should be able to look at the threads to determine if you need a fine thread bolt, or a course thread bolt. You may be able to get an insert for that big of a bolt, but it probably won't be in stock. Do not let them sell you a pipe thread reducer, it won't work, the thread count is wrong. You may have to step down one size at a time.

If you know what you need, you might be able to get one from www.mcastercarr.com. Gene

It's a fine thread but it looks strange. The threads are flat...they don't come to a point like normal. That's why I wondered if it was a weird thread. It could be that the threads are just damaged. I'll just have to try to match it up. Maybe I'll have to rig something up to make it work. The inner hole(inside the threads) measures 11/16. Maybe it was 5/8 and the threads pulled out?

I'm building my daughter a lowered "rat rod" Radio Flyer wagon. I want to use this old T handle on that. Building the frame right now. Bought a welder and I'm trying to learn as I go. Should be really cool when I'm done. I was just going to weld a bolt to the original handle tube and screw on this Hurst piece.

1/2-20 is like a lug nut stud, I don't think its that big. The Hurst T-handle I have has a 3/8" - 16 thread. I think stock mopar shift handles are threaded 3/8"-24 (fine thread).

The picture angle makes it look like the hole is 5/8 but it is 11/16. You can also see the weird looking threads. Yes, the pictures are upside down.

A 90 degree oil filter adapter bolt is just slightly too large.

I just went out to my shelf and looked at my two. Yours has been redrilled and tapped over size.

Maybe not. They make them as both direct fit in different sizes and universal with a bunch of adapters.

Universal fit t-handle

I haven't had one of those since the early '70s, but they may have had an insert, maybe brass ?
Are you sure those are threads ? They do look pounded out, but I can't think of any handle that large.
I seem to recall some with adapters, others with a jam nut in 3/8-24 or 3/8-16, which I think was GM...

I think this one takes an adapter. I don't know if the threads are supposed to look like that or if they are worn out. I'll just try to match something up at the hardware store. If I can't find anything that will work, I might have to drill it out and go larger.

Looks like an acme-type thread. Like you would find on gear pullers or tools like that.

If you call hurst/holley you might be able to buy the bushing kit separate. My bets are the bushing stayed on the shift handle when it was removed.

Maybe these will work.Inserts

See if you can find a 16mm x 1.5 bolt and see if it fits your t knob. If it does drill and tap it to your handle threads and cut it off as needed. Loctite it into your t handle. A lot of drain plugs have that pitch.

i had lots of those t-handles back in the day, and almost all of the universal "fitzall" handles with the adapter bushings were made with flat threads as your photo shows.
if you are worried about the threads, use some PINK low strength thread locker on the adapter of choice, you won't have any problem.

the most common thread sizes back in the day was 5/16-18 and 24, and 3/8-16 and 24 [fine and course pitch] for most manufacturers shifter handles.
the hurst handles were usually 3/8-24 if i remember correctly. these handles had normal looking threads.
whenever those t-handles were introduced to fit everything, i remember them having 1/2-13 threads, and adapters to fit the 3/8 and 5/16" handles. later, the thread pitch in the handle grew larger, but i don't think it ever got bigger than 3/4".
if it indeed has metric threads, i believe it has to be somewhat recently made. within the last 15 years or so ?

in any event, i wouldn't sweat the threads you have. just obtain the adapter you need and go.

It's going on a Radio Flyer wagon so I just need a bolt or something to screw into it. I'll weld the bolt onto the wagon's original handle shaft. Looks like I need to find an adapter or drill it larger and re-tap. Thanks for all the replies.

I wonder if I could solder or braze a nut inside the existing hole?

might try a heli-coil. Soldering or brazing may generate too much heat. Another thought would be to fill with JB weld and then redrill/ tap to desired thread

If he is going to fill it with JB weld, just buy an insert the size you want, then JB weld the insert into the handle. The reality is, once its on the wagon, it may never see any other use, but if it does, the threads in the hole will probably need to be fixed anyway. Who would want a T handle that wobbles around? Gene