Transfer Case

The ZF A 95 Transfer Case (with modifications for special BMW requirements) is used as a power divider. The torque of the planetary gear differential is divided with 37% of the power transmitted to the front wheels and 63% to the rear wheels. In this manner the greater portion of torque drive is transmitted by the rear wheels which promotes easy handling and maintains the typical BMW handling.




The transfer case transmits power laterally via an internal-toothed drive chain to the front drive shaft. The amount of torque transmitted will depend on the ratio of the planetary gear differential and the viscous clutch. The toothed drive chain system is known as a power transmission method having the lowest possible loss over a wide range of conditions and drive distances and also as the most compact system of this type.

Aside from periodic oil changes, the transfer case requires no adjustments and is maintenance-free.

The drive line to the rear final drive is straight via the planetary gear differential and viscous clutch.

Tension between the driven axles is prevented in the All-Wheel Drive System. Axle speed differences are compensated within the planetary gear differential and viscous clutch in the transfer case, so that any trapped stress or strain between axles is eliminated.

The shift lever is mounted higher than on the standard E30. A cast aluminum strut is used for mounting. The transmission and transfer case are mounted on a large cushioned rubber mount.