U bolt moves a bit when torquing nut

[Devils Paw 80]

So I've replaced my old rusty springs with some used OME's, along with used U bolts and nuts.

One of the U bolts, inner driver's side, twists a bit when I'm trying to tighten up one of the nuts. Can't get it any tighter and the bolt still has some noticeable movement along the top of axle when torque is applied. I'm assuming this is not a good thing and perhaps it's time for new U bolts?

 

[OSS]

Definitely-
Is the nut running out on to the non-threaded portion of the u-bolt shaft?

Remember that the torque spec in the FSM for the ubolt nuts assumes that the stock springs, rubber insulator and metal retaining clamp are all in place. That 90ft-lbs (or whatever it is in the FSM) isn't valid if any of those things are missing or changed (thicker springs).

On a brand new stock truck, that metal C clamp thingy that surrounds the spring is supposed to bottom out on the spring plate - with the 90 ft-lbs locking off when contact is reached. If the springs are thicker, the clamp thingy can't bottom out- and if the nuts are blindly torqued down to spec, the rubber spring insulator will get overly squished and destroyed.

 

[KWalkerM]

Ive never had an issue just cranking on a 1/2 inch air ratchet til its snug. Thats the non-spec way. Id back them nuts off and see if you still have threads left

 

[Devils Paw 80]

I ordered new bolts for the rear from Metal Tech. Much better price than anywhere else I could find. Ironman 4x4 FJ40/FJ60/BJ74 U-Bolt Kit

 

[Code Red]

I've always heard that u-bolts shouldn't be reused. No idea if that's true in every case, but it does seem to hint that there is a limit to how many times you can stretch them and still rely on them.

I'm not a metallurgist, but I did sleep in a Holiday Inn Express last night . . . . .

 

[Willard]

I ordered new bolts for the rear from Metal Tech. Much better price than anywhere else I could find. Ironman 4x4 FJ40/FJ60/BJ74 U-Bolt Kit

I am using these shackles on mine no issue and no run out. My first set did run out and that is why I used these. These are long enough and leave some threads. If you are using the rubber insulator not sure but they are not needed on OME springs.
As per the instructions with the shackles they said to torque to 90ft lbs (spec)

 

[slacker24-7]

I've always heard that u-bolts shouldn't be reused. No idea if that's true in every case, but it does seem to hint that there is a limit to how many times you can stretch them and still rely on them.

I'm not a metallurgist, but I did sleep in a Holiday Inn Express last night . . . . .

. Same here, I’d replace the unbolts with new

 

[Elbert]

I've always heard that u-bolts shouldn't be reused. No idea if that's true in every case, but it does seem to hint that there is a limit to how many times you can stretch them and still rely on them.

I'm not a metallurgist, but I did sleep in a Holiday Inn Express last night . . . . .

Yes this is fact....technically u-bolts should be replaced not re-used.

 

[Devils Paw 80]

Iron Man U bolts compared to stock. Problem solved.

 

[OSS]

Hmmm maybe not. That ironman ubolt looks like it's about 1" longer. That could be a problem under the truck.

 

[mattressking]

Hmmm maybe not. That ironman ubolt looks like it's about 1" longer. That could be a problem under the truck.

It will be just fine, plenty of threads to account for thinner or thicker springs, only a trim will be needed once torqued.

 

[Devils Paw 80]

It will be just fine, plenty of threads to account for thinner or thicker springs, only a trim will be needed once torqued.

Yes, I did cut them shorter once they were on hand tight. Had to really, couldn't get a deep well socket on the nuts to tighten otherwise.

 

[scrapdaddy]

Don't forget to retorque the nuts after driving awhile, they will loosen up and cause the axle to wrap up. Happened to me in Moab ( not good ).