Both ZJ axles use a four-link with rubber-bushed control arms. After 25 years the bushings are torn, sloppy, or missing chunks — they steer the truck around like a drunk pendulum. Replace complete arms instead of pressing in new bushings unless you own a shop press. The labor difference makes new arms the better deal for most owners.
Three failure modes give themselves away. A clunk on takeoff after parking on a slope is a torn lower control arm bushing on the front. Wandering steering on highway at speed is upper control arm bushing play. A "click-click-click" over expansion joints in cold weather is the rear lower control arm bushing. Get under the truck with a pry bar and lever each arm at the axle end — if you can move it noticeably, the bushing is gone.
Buying decisions. Complete replacement arms with bushings pre-pressed run $50–$80 per arm in Moog or Mevotech. Pressing new bushings into your existing arms saves money but requires a shop press, a bushing driver set, and patience for the stuck ones — figure 2–3 hours per arm versus 45 minutes for a complete-arm swap. The complete arm is the better deal unless you already have the press.
Polyurethane bushings (Energy Suspension 2.3104G) last longer and tighten up the truck's handling at the cost of more noise transmission and faster wear at the ball joint end. Rubber is fine for daily drivers. Poly is the right call if you've already accepted the squeak in trade for tight steering.
Pinion angle warning: if you've lifted the ZJ above 2.5", stock-length control arms will pull the pinion up at the front and down at the rear. Adjustable arms (Iron Rock, Currie, JKS) fix this. Stock arms with stock geometry are correct on stock-height ZJs.
| Part | Vendor | Est. price |
|---|---|---|
| Front lower control arms (pair, OE-style) | Moog / Mevotech | ~$160 |
| Front upper control arms (pair, OE-style) | Moog | ~$120 |
| Energy Suspension polyurethane bushing kit (full set) | Energy Suspension | ~$95 |
| Rear control arms (pair, lower) | Moog | ~$110 |
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.