Tech Question - Broken Center Bolt

Q -Mike,

Website information was helpful, but didn't answer all my questions. I recently (year ago) installed a lift to my International Scout. The center bolt of the leaf spring pack has just broke due to what I think was a U-bolt problem. They didn't get re-torqued. - Bo

A - Bo,

Your guess is right. There is only one cause of broken center bolts, and that is loose U-bolts.

The center bolt is necessary to hold all the leaves together and to locate the axle in the correct position. The axle is located by the center bolt head which fits into a hole in the spring seat. Then the u-bolts are used to bind the spring and axle into one unit.

The u-bolts must be tightened to the proper torque specs to eliminate any and all movement between the spring and the axle and between each leaf of the spring.

Should the u-bolts be loose two things can happen. First is broken center bolts and the second being broken leaves.

The center bolt hole is the weakest part of the spring leaf. With loose u-bolts the leaves can flex at the center bolt hole. The flexing here will eventually cause the leaf to break at or near the center bolt hole.

We do not, nor do I know of any other spring manufacturer who will warranty any spring that has broken center bolts or any spring which breaks between the u-bolts.

When installing new spring be sure to use new u-bolts. Attempting to re-use the old u-bolts is being penny wise and pound foolish. Go read All about u-bolts and torque.

Keeping u-bolts tight will extend the life of any spring. - Mike