The TJ has a Ford "Sterling" 10.25-inch rear axle. This axle has been fitted with Yukon Gear & Axle 5.13:1 gears, Dodge disc brakes with four-piston calipers, and a Detroit Locker. The Duncan's 4x4-built rear suspension is a departure from the front, having only a three-link setup in common. Instead of air shocks, it uses coil springs with BDS shocks. The result is a flexy suspension that generates about 18 inches of travel. The upper and lower links are fabbed from the same material as the front links. They use polyurethane bushings at the axle and 3/4-inch Rubicon Express Super-Flex joints at the frame. The track bar is made from 2-inch-diameter, 0.250-inch-wall DOM tubing and it also has Super-Flex joints at both ends. The rear chassis has been significantly reworked and a new crossmember has been added. Other mods include upper coil spring buckets that are recessed into the frame.