Tech Question - U-Bolt Torque

I painted and installed the new springs I received from you and was following the Ford manual to torque the U bolts.

They had a range from 30-45 ft lbs and we stopped at 30 because the axle pads were getting extremely smashed and the upper and lower plate were almost touching. I notice your web site states 45 ft lbs for 7/16 U-bolts which is what I installed.

Can these be these be torque with the vehicle sitting on the ground?

I am hoping the test drive did not damage them, it was only a couple of miles but we put some stress on them to see if the vehicle would hook up.- Steven

Steve,

First, snug up the u-bolts while the vehicle is in the air, then torque them when the vehicle's full weight is on the springs. Then re-torque again after 50 or so miles. Then check the torque any time you are under the car.

Now, while we do show a torque of 45 foot Lbs. for a 7/16 u-bolt, we also say to follow the Manufacturers recommendation. In your case this would be a torque of 30 to 45 foot Lbs.

But as you pointed out the rubber pads were being squeezed. The rubber is there to help the rubber spring eye bushings isolate the suspension from the road imperfections. Nice thought but bad idea.

The weakest part of any leaf spring is the centerbolt area. The purpose of the centerbolt is not only to clamp all the leaves together, but also to locate the spring to the axle.

Any movement of the spring in the u-bolt area will cause the springs to break. So ideally, the spring should be clamped metal against metal with no rubber axle pads.

The sad part is, no matter what you torque the u-bolts to, the torque will not remain there because the rubber will continue to "give".

But, heck, the old springs lasted for years and so will the new ones. So go forth and enjoy. - Mike