Description Much of the jarring ride of the leaf-sprung rear can be attributed to the factory vulcanized bushings in the leaf spring pack and shackle. The factory shackle is very strong BUT the design is not conducive to a smooth ride. This is no surprise as these trucks were not made to ride well, they’re made to tow. The factory leaf springs are high-spring-rate and short-travel, why would Ram design a shackle that rides well and is capable of extended suspension travel? Vulcanized bushings are a press-fit bushing often utilized by OEMs in which the bushing material is adhered on both points of contact. In contrast to the factory bushing, the Carli Bushing assembly utilizes more bushing material and a thinner sleeve to prioritize ride damping. Further, our bushings are serviceable. Droop the rear end and grease them through the protected zerk fitting. You’ll note in the high-res pictures, there are channels for the grease from the zerk. The grease travels through these channels, around the crush sleeve and to the bushing face for optimal grease migration and bushing life. If you do manage to wear out the Carli Shackle bushings, you purchase new ones and swap them in; reuse the crush sleeve. The factory shackle requires replacement in its entirety when the bushings crack/rot. In short, the factory shackle is beefy BUT utilizes a press-fit vulcanized bushing designed to bind and resist movement. This makes for a crappy ride, no serviceability and no rebuildability. The Carli shackle costs less than a pair of American-Made sneakers and works wonders to free up the rear end of your truck (even fits factory leaf springs) while offering BOTH serviceability and rebuildability. features Greasable and Rebuildable Far Better Ride than Factory Shackle 1/4″ Steel Construction Fits Factory and Carli Springs Fitment: 2003-12 Ram 2500/3500 4×4 Fitment: 2013+ Ram 3500 4×4