Symptoms
Flaking, swollen or holed frame around the rear lower control-arm brackets, clunks from the rear, or a bracket that moves. Quadratec warns it can lead to structural failure.
The fix, step by step
- Rick Rotondo's Quadratec guide on a 1998 TJ: support the frame on stands, remove the rear wheels, hold the axle on a jack, and unbolt the upper and lower arms, sway-bar link and shock on one side.
- Mark at least 1 inch of overlap past the rot, then cut out the bad frame, the sway-bar mount and the factory arm mount.
- Avoid the brake hose and fuel lines, and do not cut the body mount.
- Mock up the replacement section, trace and grind to bare metal, tack weld, recheck measurements, then fully weld.
- Prime and paint or coat it, refit the arms with Loctite, torque everything to spec, and recheck after a day.
- Rotondo says it's only for people experienced in cutting, grinding and welding.
Tools & part numbers
- Floor jack and stands
- grinder
- cutting wheel
- welder
- primer, paint or POR-15
- torque wrench.
Where to buy the parts
Rust Buster rear trailing arm mounts section, 97–06 TJQuadratec ↗Amazon ↗
TJ body & frame repair partsQuadratec ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Wrangler TJ parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.