SuperPro SPF1975K Rear Differential Pinion Mount Bushing Kit (without Active Yaw Control 45mm O.D.)SuperPro SPF1975K Rear Differential Pinion Mount Bushing Kit (without Active Yaw Control 45mm O. D.) Note: Fits Evo models without Active Yaw Control. For models WITH AYC; use SPF2543K This kit replaces the forward differential mount bushings known as the pinion mount bushings. The OEM units are soft rubber and break down fairly quickly with that wear accelerated the harder they are used. The worn bushings allow more movement of the rear differential