As a general rule, your Jeep Wrangler u-bolts should be replaced anytime you make major changes to your suspension system, since they are inexpensive and absorb a lot of abuse. These essential components connect the axles to the leaf spring packs and will wear out much more quickly if you take your Jeep Wrangler off the beaten path. While it rare for these parts to actually break, they can and do stretch, bend, and crack. A quick visual inspection should tell you whether or not your u-bolts are in fine fettle. If there are any signs of wear, rust, pitting, or other infirmities, they should be replaced as soon as possible. Failure to do so could result in damaged to other more expensive parts and components.