Note to DUMBA$$ SELF........

If you'd like to remove your Front Axle in the future, you may wish to remind yourself to re-lube your threads after Brake-Cleaning off the Cosmoline.....

 

Sheesh
I take it they galled up on you?


What a bummer
Bobby

 

Yup, while I was trying to remove them.

They'd unscrew for a while but the damage was done. After the first one, I applied anti-seize to the rest before attempting, but it didn't help much. Figure at 115lb/ft, the mating pitch diameters got plenty hot and the doo-doo was already balling up. Probably never achieved the actual torque.

Ran down to C&G and got fresh parts. I know better but I guess I'm getting senile....

 

Before you torque your new bolts down, check out what Eaton says... They say a 9/16" u-bolt gets torqued (with lubed threads) to "about" 65 ft-lbs. As I recall, stock u-bolts are 1/2"? That's a LONG ways from the 115 the book says.

PS -- a sawzall works great on those, too!

 

Since my Truck was a Heinz's 57, I don't trust anything that came off it as Gospel. That said, the original front bolts that I kept are 9/16" and the Axle holes seem to agree.agree. I think the Rears are 1/2"... Interesting though that the spec is 108-125. That's a hell of a lot different than what Eaton says.

 

There would be a difference between dry and lubed threads. Anti seize on the threads would require even less torque.
Mark

 

That video has me questioning stuff now. Why would modern ubolt threads be rolled instead of cut?
Shoot, I had never heard of having rolled threads until I saw the video.
When I replaced my rear u-bolts I went to a big truck shop, gave him my old ones and they made new ones and cut the threads. Seemed to work slick. That was actually as tight of a bend they could make in their dies. So if I need front u-bolts I will probably need to order them.

By the way, those are cute little u-bolts in the video. Our trucks would eat those alive.

 

Most all bolts, production made, have rolled threads. I had my u bolts made at Premier truck parts and they are cut threads also. They wouldn't do enough threading to justify thread rolling equipment for each size thread they would use. Contrary to what was said in the video, rolled threads are generally stronger than cut threads and they ARE reusable. If they deform from tightening the nut, it is from over torqueing, or torqueing beyond the yield point of the threads. 65 Ft lbs on a 9/16" bolts will not deform the threads unless they are made from mild steel. If that were the case I would buy my u bolts elsewhere. I would use good quality u bolts and torque them to the spec Ford specifies.
Mark

 

I agree on most counts. Except for very small u-bolts like for Harbor Freight trailers, all the u-bolts I've had were threaded from rolled stock for the particular order, all cut threads.

Looking at bolt torque limit tables on the web, the 115 ft-lbs in the manual appears to be right at the limit for yield on Gr 5 material. I don't know if that's where I'd want to be.

 

I would agree with the video that most u bolts should not be reused, not because they have rolled threads, most are pitted so deeply from rust. If what he said was true, that tightening the nut on rolled threads deforms the threads and makes them where they cannot be reused, we would be replacing virtually every bolt we take off of our trucks. There are only a handful of threads on them that aren't rolled. I would imagine that the original Ford u bolts are better material than grade 5.
Mark

 

Hah! Youze guyz are bringing me out of Retirement......

Rolling threads is the practical, cost effective method to produce Class 2 bolts in production quantities. The dies work-harden the threads and the grain structure is smoothly re-formed. Cutting threads will produce Class 3 precision, but the grain structure gets micro-mangled. Under load, stress-cracks are more likely to propagate resulting in failure. .....

For our Trucks where the objective is clamping (rather than precise adjusting or locating), Class 2 rolled threads are the norm. The only drawback to formed threads is that often, tolerances aren't held, and clearances get sloppy.

With my U-Bolts, whatever the alloy/heat-treatment is, I can say my Die-Grinder with a 1/16" cut-off wheel worked very hard to cut through. I initially tried a pneumatic saw with a bi-metal blade and it hardly scratched them.

Because I haven't bored you enough.....

A word of caution with plated hardware in critical applications such as Suspension, Roll Cage/Harness Restraints or Towing.

I personally won't use Chrome, Zinc, or Cad plated hardware in critical areas. Almost all hardware in the world today is produced overseas and yes, they still use Cadmium.

During the plating process, Hydrogen impregnates the steel grain structure. After plating, the Hydrogen wants back out creating extreme internal stress The steel becomes hyper-brittle (Called "Hydrogen Embrittlement"). To out-gas the Hydrogen completely, the bolts must be baked 12-24 hours depending on process. In Taiwan as a reference, I discovered all Plating Houses bake for 3 hours period. So some out-gas baking does occur but to me, it's a crap-shoot I'm not willing bet my life on.

 

Ernie, are your u-bolts cut threads or rolled? They look cut to me.

 

Your making me bust out the strong Glasses.

They're cut annnd....I gave You and Everyone incorrect info. It's a 1/2" U-Bolt like you said. I was boxing up some 9/16" Nuts beforehand and my brain ran with it.

 

Fronts are 1/2 and rears are 9/16, so we're both right. And I don't see how the F & R can have the same torque spec?! I think I'd go back with 65 ft-lbs, see below. They're USF threads, right?

 

Yup, as I mentioned, I don't trust anything on my truck as being original. I know my rear U-Bolts aren't, but I think the spring plates might be. Those Bolts are 7/16". So I need to take a closer look at the Plate hole diameters and ensure everything is correct. I received the Truck that way. The bolts are actual "u" shaped around my '60s 9". I did cinch those bad-boys down hard too.