Symptoms
A rear end that sags below the front, bottoms out on washboard, or sits on the bump stops with a full load of water, fuel and gear.
The fix, step by step
- Weigh the loaded truck first.
- Expedition Portal owners say the rear axle and suspension are the weak points under long-term heavy loads, and recommend springs and shocks rather than frame or axle changes.
- Support the frame, lower the axle on a jack after disconnecting the rear shocks, sway-bar links and track bar if needed, then swap the coils and fit the matching jounce bumpers.
- Refit at ride height and torque the suspension bolts with the Jeep on its wheels.
Tools & part numbers
- Floor jack and frame stands
- sockets
- torque wrench
- spring compressor not usually needed on JK rear coils.
Where to buy the parts
Skyjacker dual-rate rear coil spring pair, 2007–2018 JK UnlimitedQuadratec ↗Amazon ↗
OMIX 18280.26 rear coil spring jounce bumper, 2007–2018 JKQuadratec ↗Amazon ↗
JK coil springsExtremeTerrain ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Wrangler JK Unlimited 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.