The rear radius (swing) arm pivots on a shaft that can wear over time. Our kit includes the shaft, bushing, bearing, thrust washers, seals and hardware to complete the job. The bushing must be reamed/honed parallel with the centerline of the pivot hole, so it requires assistance of a machine shop. Cars before 1963 need an extra 2A7325 for each side, and the needle roller bearing is not used. Kit does one side ony, use two (2) kits per car. Genuine Unipart.