ZJ Quadra-Coil rear is a four-link with coil springs — same architecture as the XJ and TJ rear, with two lower arms, two uppers, a track bar, and a coil over each spring perch. Service is straightforward once you know to support the axle before you unbolt anything.
The Quadra-Coil name was Chrysler's marketing for "coil springs front and rear" — there is no air, no electronic damping, no exotic geometry. Front and rear are both solid-axle coil-sprung four-link setups. That's part of why the ZJ runs circles around the later WK on a trail: it's a genuinely capable platform with straightforward suspension. Stock coils sag after 25 years and will let the bump stops touch the axle tube on a hard compression. Stock shocks are toast on any ZJ that hasn't seen new ones in the last decade.
Decisions before you order parts. If the ZJ rides like a brick and sits low in the rear, replace coils and shocks together. If it rides okay but bottoms out over speed bumps, do shocks. Bilstein 5100 is the gold-standard street/light-trail shock for a stock-height ZJ. Rancho RS5000X is the budget pick. Monroe and KYB white-box shocks are economy options — they work but won't outlast Bilsteins.
Lift options: A 2" lift spring upgrade is the sweet spot for 31" tires. Iron Rock Off Road, Old Man Emu, and Rusty's all make ZJ-specific 2" lift coils. Anything taller than 3" on a ZJ requires adjustable control arms and a longer track bar — see the related control arm guide.
Service interval: shocks every 60,000–80,000 miles, springs only when sagging or damaged. Inspect upper coil isolators every shock change — they crumble and let the spring contact bare metal.
| Part | Vendor | Est. price |
|---|---|---|
| Rear coil springs (stock height, pair) | Moog / Mopar | ~$130 |
| Rear shocks (pair) | Bilstein / Rancho / Monroe | ~$140 |
| Upper coil isolator (pair) | Mopar / Crown | ~$22 |
| Sway bar end links (pair, if rotted) | Moog | ~$35 |
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.