The Stovebolt Site Forums The Shop Area General Truck Talk Tierod Thread Size 48 3100

I need to narrow the tierod on my 48 3100 because I recenlty put in a dropped axle. Does anyone know what kind of thread it is? Is it standard 3/4 pipe thread?

rsg2506 -
It could be a 3/4 pipe thread. :confused: If it is, I would be interested in knowing. I never thought of a 3/4 pipe thread when I was trying to shorten my tie rod and I never could find a thread that worked. :mad: A 3/4" nut will screw on to the end of the tie rod, but it's probably closer to a 13/16" thread, but I could never find a 13/16" die.
If it was me, I would get my hands on a female 3/4" pipe nipple and see if it would screw onto the tie rod.
Good luck!!

Joe

Not pipe thread as pipe thread is tapered. Probably 25/32"-16, which is an oddball thread that you will have a hard time finding a tap for.

You bent your steering arms in to clear the tires, and that's why you need to narrow the tie rod? Maybe you could make a new tie rod using some more common sized tie rod ends? Just an idea.

You will need to measure the outside thread diameter to know for sure. Using calipers or a micrometer, it should measure slightly less than the decimal equivilant. 3/4 (.750) could be as small as .740. You will then need to count the number of threads per inch. 3/4-10 (10 threads per inch is coarse) 3/4-16 (16 threads per inch would be a fine thread). There is an almost infinite number of thread combinations that can be machined. I would guess that you have a typical fine thread (or SAE) as some would call it.
I would have to agree with Barry. It is unlikely that it is a pipe thread, as this type of thread is designed to bottom out (on the taper) to form a seal.

J Lucas

Thanks for the feedback guys. When they dropped the original axle, it moves the king pins inward about an inch on each side due to the stretch. I'll take a micrometer and see what the diameter is and check the threads per inch. Hopefully it's not an oddball size. I've read a few other posts where another member shortened his original tierod, so I'm hoping the thread is somewhat common. I've already ordered the newer style tierod ends from Chevyduty, so I'd like to use the existing tierod.

Right hand thread AND left hand thread. Reassess your problem. I'm thinking your friendly local machine shop could do that job for you for much cheaper than buying L+R hand dies of oddball sizes that you will never use again.

Cosmo,
Thanks for the tip. You may be right. Is there a reason I would need to shorten both sides of the tierod? It seems like I could just cut off the right hand thread side, shorten and rethread it? If it's a standard 3/4-16, they cost about $7. I think if it's an oddball thread, the machine shop is probably the better way to go.

Thanks again,
-Rich

It's definitely not a 3/4 pipe thread. I check that out last night.

I've been through this situation myself and engaged the help of Barry Weeks at the time. Between the two of us - mostly him, we found no dies available that are that thread size and you can totally forget the the left hand thread. You probably could find a LH thread at an old shop somewhere or a fully equipped shop. It's such an odd thing, they are difficult to find. Finally, we cut off the RH thread end and re-threaded it with a 3/4-16 die. It worked fine.

About the only other thing you can do is cut the tie rod somewhere in the non-threaded area, remove the a portion and weld it back together to the length you need.

I think we all would be interested to hear if you do come up with the dies you need and/or what you end up doing!

Joe, I would love to find some left and right hand taps and dies in that 25/32"-16 size. I go to alot of machine shop auctions and stuff and someday I just know I'll find a whole box full sitting on a shelf gathering dust, and I'll be the only bidder at a $1.00!

If you can't find a die to rethread the RH side, I think the cutting and welding idea would work good. Cut, grind a large "v" groove in it, and weld or have a good welder weld it if you can't. Before welding, find or make a pipe-like sleeve (maybe 6" long) to slip over the welded joint after it's done, and then weld each end of this sleeve onto the tie rod to reinforce the joint.

I measured tonight and the threads are 3/4-16. I had a 3/4-16 tap on hand and it ran into the tie-rod ends without a problem. I'm going to pick up a 3/4-16 die and I'll update when I get everything in place. Thanks for all the help guys.

-Rich

Way to go rsg!! Nice solution Barry.