4x4 Front LeafSpring U-Bolt Question ?

[54blackhornet]

I need to remove the front axel from my 71 K-10. What size is the gigantic nut holding the U Bolts on ? And can I reuse them or should you replace all the original hardware when reinstalling the axel ? Thanks

[DirtyLarry]

It is always a good practice to replace u-bolts when ever you remove them, especially if they are the originals. Most cities have a driveline shop that can build them for you or you can buy a set through ORD. ORD does have very nice u-bolts whereas some of the u-bolts available from other suppliers are cheesy. Basically you want a u-bolt that has the long nut and hardened washer. Do not accept any u-bolts that use nylon lock nuts. Those nuts are very soft and often strip before you even reach the torque spec.

Oh, if you are asking what size socket to remove the nut, I believe it is a 7/8. The rod thread diameter is probably 1/2" to maybe 9/16" on a half ton.

[54blackhornet]

Thanks for the information ! I am going to need a bigger wrench I guess ? I heard from others to use new hardware but an old mechanic friend said that is B&@Sh#T ! Just check for cracks, clean up the threads, repaint with rust oleum and get the torque correct ! I spoke to ATS Spring and they suggest installing all new UBolts and hardware, they stretch during torque procedure.

[73chevy95]

Ruffstuff makes some pretty good u-bolts for cheap, I agree to replace em like dirtylarry said, better safe than sorry!

[LONGHAIR]

Cut them off and get new ones, but be aware that there is significant pressure there. It will "pop" when you cut them.....torch or cut-off wheel works great. Put your effort into things that are worthy, unscrewing rusted u-bolts just plain sucks, even with an impact. They just rattle around and the power is wasted.
Like Larry said, you want the "long" nuts and hardened washers....a little lube on the threads is good too.

[cableguy0]

U bolts stretch a ton when they are torqued in the first place. They need to be replaced. Also do not use an impact gun to tighten the new bolts. They will not be tight enough because they are springy the gun will just make them bounce.

[54blackhornet]

Thanks for the insight about the U-Bolts, I took a shot at removing one with a wrench and noticed that the threads where all screwed up at the bottom of each bolt. I will use the torch method this weekend. Would it be better to drop the leafs out from the frame first ?

[Rubble]

If all your doing is swapping axles,just use a torch or zip wheel & cut the u bolts.Dropping the spring out is a lot of extra work.

[kwmech]

If they are factory bolts, then they are 5/8 requiring a 15/16 socket. In an ideal world they should be replaced as the bolts are a rolled thread and the nuts are a cut thread, thus when you torque them correctly the threads interfere somewhat locking them in place. On a couple of trucks I have, I used them over without any problems