For a leaf spring suspension to operate smoothly the springs and shackles must move freely without binding. To eliminate this problem we recommend Daystar's 'Zero-Bind' technology. Daystar Dura-Thane Greasable bolt/bushing kits come complete with gun drilled, hardened bolts, grease grooved Dura-Thane bushings and nylock nuts. Zerk fittings are placed for easy access and can be filled with any standard grease gun. Replacing your stock spring or shackle bushings with one of these kits will help to eliminate annoying squeaks and the bind.