Front lower control arm mounts crack and rip out of the unibody. Visible cracks at the inner frame rail where LCA bolts. Weld-in reinforcement plates required.
The front lower control arms bolt to a tab/pocket welded into the bottom of the unibody frame rail. On any XJ with significant off-road use, lifted suspension, or northern rust, these mounts crack along the welds and eventually tear free. Symptoms: clunking on acceleration/deceleration, visible crack at the LCA mount when viewed from underneath, control arm bushing chewed up. Inspect by jacking each lower control arm individually and watching the mount for movement under load. Repair: weld-in reinforcement plates from M.O.R.E. (BL2030), Rusty's Off-Road, RuffStuff, or Iron Rock. Boxing kits also strengthen the entire front unibody rail, recommended for any XJ with 4+ inches of lift. This is preventive maintenance on stock XJs; mandatory on lifted/wheeled rigs. The aftermarket repair plates wrap the mount and weld to undamaged metal, restoring strength better than original. Plan a weekend with a welder.
| Part | Vendor | Est. price |
|---|---|---|
| Frame stiffener kit | M.O.R.E. | ~$175 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.