AKG Motorsport Differential Bushings, Aluminum – E46, Z4 (Non-M)Product Description These BMW E46, Z4 (Non M) Aluminum Differential (Diff) Mount Bushings eliminate all differential movement for effective power transfer to the rear wheels. The stock rubber diff bushings deflect as torque moves through the drivetrain, which allows the differential to move. Eliminate this movement and allow your diff to operate effectively with our BMW E46, Z4 (Non M) aluminum differential bushings. Although our solid aluminum BMW