Leaf Spring Shims

[thebird00]

I had a problem with U bolts loosening up on me, even after short drives. Upon further inspection I noticed that the U bolts nuts were not loosening, but the shims were actually flattening out. It's doing it worse on the driver's side where the perch was caved in slightly. But the passenger side with the fixed perch is also doing it, but not as bad yet. The fellow I spoke to at superlift said he had never heard of this happening before. From my past experience with other Superlift kits, they never seem to have heard of any problems with there kits before. He confirmed that they were aluminum shims. My question is do you think I should go back to superlift and replace the shims with more aluminum ones or try to find some steel ones? I'm going to replace the perch while I got it all back apart. The lift itself probably only has 500 road miles on it and no real major wheeling miles. Superlift recommended 100 ft. lbs on the U bolts. I just crank down on them which could be the cause of the problem. Anyone every had this problem before?

Thanks, Mark.

 

[sandawgk5]

I would get steel ones and bolt them to the pack. JKWOFFROAD sells them in varying degrees of angle and I think Kert at DIY4X could make you some for a reasonable price. Aluminum ones will break and apparently they like to flatten out (never seen that before).

One of the pics make it look like the shim is coming out of the pack like it is not centered on the pin anymore.

Ira

 

[thebird00]

I just can't see the reasoning behind sandwiching a piece of aluminum between a steel perch and a steel spring.

Btw, they are 12 inch superlift springs.

 

[Currank5]

I had the same problem with the shims on my truck also. They were aluminum and when i took it apart it had acutally broken into several pieces and seemed to be shifting. This may explain it flattening. I went to a local spring shop and they matched it up with some new ones. I think they are brass but they fixed the problem.

 

[rcamacho]

Part of the problem may be the spring profile at the axle pad. Some manufacturers flatten the spring at this point in order to improve solidity of the mount. With the high arch curvature, number of leaves it looks like the spring could rock on the pad even when fully torqued. - It might be contributing to wearing out the shims.

Otherwise ditto on steel shim bolted to spring pack.

 

[thebird00]

U bolt torque

Thanks for the responses.

What do you think I should be torquing the U bolts to? 100 ft lbs seems a little low.

 

[sandawgk5]

Thanks for the responses.

What do you think I should be torquing the U bolts to? 100 ft lbs seems a little low.

Hit them with the impact and then put the breaker bar on them. In all honesty I think mine are about 160 Ft-lbs

Ira