Thread size for '48-'52 F1 Leaf Spring U-Bolts
 

Guys,


I am cleaning up a '52 F1 front suspension that I have and I need to chase the threads on a couple of the leaf spring u-bolts. I measured the u-bolts with a caliper and they appear to be a nominal 9/16" in diameter. The threads are fine threads which leads me to surmise they are 9/16-18 UNF.

I checked some sites like Mac's and Dennis Carpenter to see if the thread information was available but I was unsuccessful.

Before I commit to buying a die to chase the threads I thought I would confirm this with the experts here. Have I surmised correctly?:rolleyes:

Thanks!

Re: Thread size for '48-'52 F1 Leaf Spring U-Bolts
 

C&G (800) 266-0470 has them for 48-52 pickups, Order B3C-5455-A You will need four. Order nuts, as well. The U-bolts cost $7.95 each It is a very good idea to install new ones. Old ones are usually rusted, making proper tightening uneven. Ford has always used odd thread pitches, so we save all threaded pieces and bolts for future use, if needed.

Re: Thread size for '48-'52 F1 Leaf Spring U-Bolts
 

The thread size is indeed 9/16-18.
48-52 uses 01Y-5455-C for the "U" bolts. The nuts are 33848-S7
The lock washers are 34850-S

A regular cutting die will definitely "chase" threads.... it will also
remove metal, which you really don't want to do. A thread chaser would be better.

I used McMaster-Carr for the nuts, which meet the SAE standards for
nuts used in this application....

https://www.mcmaster.com/90565A333/

Re: Thread size for '48-'52 F1 Leaf Spring U-Bolts
 

If you get a split die you can adjust it so it will not cut more deeply than necessary. You will need a die holder that is either offset so the handles clear the U bolt or one with removeable handles and substitute shorter handles for the job. A hex die nut is ideal but won't be adjustable, but should be sized right so it does not take too much off.

Mart.

Re: Thread size for '48-'52 F1 Leaf Spring U-Bolts
 

A local truck spring shop bent me up a set of 4 U-bolts to order, with new heavy washers and deep nuts, for $25. They did it while I waited. No way I'd re-use 68-y.o. bolts on a front end.