The Stovebolt Site Forums The Shop Area General Truck Talk Odd size nuts

I pulled the old gauge clusters out of my dash on a 54 chevy pickup and like an idiot I didn't save the parts.
I'm putting in some new gauges and I can't find nuts that will fit the studs that protrude from the back of the dash.
These are the 6 studs, 3 around each large hole, that mount the gauges in the holes. I've tried 10-32 and 10-24 nuts. They don't screw on.
Anyone have an idea?

You know, Brian, I just redid my gauges last winter and don't remember the size. Can't check right now 'cause I'm at work.
HOWEVER, Cletis says in a thread under "instrument panel gauges", posted last August, to replace them with 1/4 20 knurled brass nuts. Thataway, you can tighten and loosen them with your fingers.
Also, if your '54 has a radio grill, the atttaching hardware is the same size.

The 54/55 do not use the brass nut they use pan nuts available at about any auto parts store. If you put the smaller brass nuts on them you will strip them. These were in common use by GM in the 60's and 70's for things like emblems and lights.

I replaced mine with 'wing nuts', makes install a one beer job.

Agreed,they did not come from the factory with brass nuts but using them makes the job easier. You must have powerful fingers if you can strip 1/4-20 brass thumbnuts with them.

Not the nuts it damages the posts if you cross thread or mess them up that is a bad place to do it.

No matter what you use.. don't mess them up.

I can't see any increased likely-hood of messing the studs up by using brass thumb screws/nuts of the same thread size.
Grigg

Pan nuts do nut cut the same threads as the brass think about it, pan nuts cut a thread by their design using a single thread line. This is a very coarse thread line different than the brass nuts. I parted 3 1954 trucks this year they all had pan nuts no brass!

I don't remember the size, but I can check with a thread gauge when I get home.

yeah, the problem isn't what type of nuts to use, the problem was finding any kind of nuts that would fit. 1/4-20 would be too large I think.

The studs have a small lead without threads. 10-32 and 10-24 will fit over this lead but then bind on the threads.

I was looking for the pan nuts, I think by that you mean the stamped formed nuts. My local Ace didn't have them.

I found some nylon spacers that had an ID that seemed to be about right. The nylon will allow the stud to cut its own thread without damage. I agree, you do not want to mess them up.

They may be 12-24 or 12-32, neither of which are very easy to find, but they do exist. They are a little smaller than a 1/4 nut, but, of course, larger than a #10. Try a good fastener place.

metric

The size is 12 and I think the thread count is 28. I can't get good enough light to be sure.

Thanks, I'll look for those.

Those nuts are definitely not metric. You should be able to match the ones on the radio grill as mentioned.

And I thought someone was feeding me a straight line.

I used #10-32 nuts on my radio grill. They fit right. ................OK, so I just ran out to the truck and spun a new 10-32 nut onto the back of my guage and it also fit perfect. Of course mine is a '53 GMC.........if that matters.

My 1954 Chevrolet gauges are each attached to the three posts on the underside of the dash with 8-32 nuts (I can post pictures of nuts on Sunday, if anyone asks). I like Cletis's idea about using brass knurled nuts .

10-32 nuts might fit but they would be a loose fit.

47-53 gauges might have different posts/nuts and 54/55 GMC gauges are completely different from 54/55 Chevrolet truck gauges.

My 52 is 10-32 also,I wish I had thought of brass knurled nuts before I put my dash together or the wing nuts.Good idea.

Pete

The more I think about it I believe mine were 10-32 also. Guess I need to go find my old post and correct it.

Why would there be different sizes floating around? The 10 nuts will only go over that shoulder brihill18 talks about and will not thread onto mine or apparently his.

brillhill18 is referring to a 1954 Chevrolet truck. What are you all referring to?

Brian,

I have three 1954 Chevrolet trucks, on all but one the threads on the posts were badly mangled. I had some threads that were so mangled that I could not remove the nuts without either destroying the nut or destroying the post. The measure I gave above was for a good post with clean threads. I used a stainless steel nut as a test-fit (it fit tightly but it smoothly went up and down the entire length of the post). I then measured the diameter with a bolt gauge and the threads with a thread gauge.

Mine are definatly not 10-32 or 10-24
I've tried both of those.

12's or 14's?

Been watching this thread wander all over the place, so I figured I’d throw my offering into the soup. These are just some thoughts on how I view this subject having removed my instrument clusters to replace gauge and clean them.

The thread on the studs of the instrument cluster of my 1950 AD are #10-32, I see no reason why they would use any stud that was larger than that to hold the instrument clusters in place on any of the later units.

Unified American Threads only come in certain sizes.
There is no #14 in the Unified American Thread system
All you have to do is mic the major diameter of the thread to find out what you’ve got.
Thread Size Major Diameters
#8 -------------------- .163”
#10 ------------------- .189”
#12 ------------------- .215”
1/4” ------------------ .246”
An inexpensive thread gauge will tell you your pitch.

If your thread is messed up from a previous owner then chasing it with a die is an easy enough task after you have determined the size and pitch. Dies are available from places like McMaster with a 13/16”od that should allow you to chase the thread on the instrument studs. Most decent Hobby Shops also carry small number size dies also.

Although the “Pal” nuts or “Push” nuts may have been used on the later vehicles to speed production, they are not the best fastener to use. You’re better off just pitching them and using a standard nut as they can damage the screws threads. Brass nuts are a good sub for the original nuts because they are not prone to rust like the steel nuts are. The thumbscrews are a good idea if you plan on removing your instruments often but a hex nut and star washer is the best choice since most people will only need to pull their clusters once or twice, if ever in all the time that they have their trucks.

Here is a quote from a commercial vendor about the use of Pal-Nuts:
“Pal-Nuts are a push-on nut that is reusable and can be used with a threaded or non-threaded stud. Why fiddle with a washer and nut when you can just use a Pal-Nut that has the washer built in? Just push the Pal-Nut on with a socket wrench and move on”

Denny Graham
Sandwich, IL

Let's try this again.

My 1954 Chevrolet gauges are each attached to the three posts on the underside of the dash with 8-32 nuts (a photo is linked-to below). I like Cletis's idea about using brass knurled nuts .

10-32 nuts might fit but they would be a loose fit.

47-53 gauges might have different posts/nuts and 54/55 GMC gauges are completely different from 54/55 Chevrolet truck gauges.

brillhill18 is referring to a 1954 Chevrolet truck. What are you all referring to?

Brian,

I have three 1954 Chevrolet trucks, on some of the posts the threads were badly mangled. I had some threads that were so mangled that I could not remove the nuts without either destroying the nut or destroying the post.

The 8-32 measure I gave above was for a good post with clean threads. I used a stainless steel nut as a test-fit (it fit tightly but it smoothly went up and down the entire length of the post). I then measured the diameter with a bolt gauge and the threads with a thread gauge.

These are 1954/55 Chevrolet truck gauge-cluster attachment posts' nuts. The machine screw in the photo is #8-32. This is a perfect fit and is exactly the same post diameter/thread as on the back of the dash (on all three of my 54 Chevrolet trucks).

Why Chevrolet used this diameter and thread is of minimal interest to me. I do not need a reason - I just use what I find was originally used.

The nuts are not push nuts but "Pal Nut Capped Washer Self Threader". They are sheet metal "cap nuts" with a small slit in the top radiating out from the center-opening, most likely to act as locking feature.

"Pal" nut.
http://www.mrgusa.com/pdfs/83-89palnut.pdf
Yes '54> must be different than <'53.
DG

Check the link I added above (part/nut number: SD188008), Denny.

Intresting feedback.
My threads are OK, not messed up at all. I just had unscrewed the existing nuts off without a problem, I think a 3/8ths socket was what I used, and then swept up the nuts with the rest of the debris and tossed it all.

You're picture shows a stud without the lead that I mentioned, a area about an eigth to a quarter inch without threads, that is slighlty smaller in diameter than the treaded portion. The 10- nuts fit over this but then do not screw onto the threads more than a half turn before binding, neither the -24 or -32 make a difference.

I'll see if I can get a picture tomorrow and post that. Meanwhile, I will keep poking around.

Just push a small piece of rubber vacuum line over the stud and be done with it.