Rear Axle

Rear Axle





The rear axle for the (E85) Z4 is very similar to the E46. The roadster adapted kinematics has resulted in several modifications:
^ The track width has been widened by 30 mm.
^ A reinforcement plate with cooling duct (for differential) is installed to increase rigidity.
^ The rubber bushings on the sub frame and on the trailing arms are harder.
^ The brake hoses, brake pad wear sensor wire and the wheel speed sensor wires are routed on and underneath the trailing arms (additional brackets on arms).
^ Three different cave shafts (length) are used in the (E85) Z4 depending on the transmissions.
^ Two different output shaft sets with constant velocity joints:
- M54B25 (manual and automatic) and M54B30 (automatic) 31.5 mm diameter.
- M54B30 with GS637BZ manual 38 mm diameter.
^ Due to underbody aerodynamics, the rear axle differential aluminium cover has cooling fins to ensure sufficient cooling (lifetime fluid fill).