Powerflex Rear Differential Rear Mounting Bush For BMW G8X & F8X VehiclesPowerflex PFR5 4026 is a replacement bush that features a built in support washer, providing further stability of the diff under acceleration. PFR5 4026 can also be used in conjunction with our PFR5 4030 dual mount rear differential bracket to mount two bushes into the factory positions. Made using our signature Purple 80A durometer polyurethane and Black anodised 2011 T6 aluminium, to reduce drivetrain deflection and the potential for wheel hop