Permanent all-wheel Drive with
    straight-mounted Engine

Assignment

This construction was probably the first successful test of a permanent all-wheel drive. With this drive type, the otherwise, not driven axle, is not selected when required, but permanently engaged with the drive-train.The permanent all-wheel drive also has advantages on roads where the surface offers good grip. The drive torque is distributed to both axles. Thus, more cornering force is left over for the previously single driven axle. If the disadvantages were compensated for (weight and performance loss), a car with permanent all-wheel drive should be able to be driven faster, also on dry and winding roads, or it should offer more safety reserves.

Function

The most elegant realisation of an all-wheel drive is probably possible with a front-wheel drive and a straight mounted engine. Apart from the changes in the gearbox, with the housing almost unchanged, the drive train needs "only" to be complemented by a center differential, a cardan shaft and a driven rear-axle. Both of the latter two parts are basically, components from the serial production of the standard drive-train. With a front-wheel drive, the complexity of the conversion, for the manufacturer, to all-wheel drive, is lower than that required for the conversion of a standard drive train.

The (lower) transmission output shaft is decisively changed. It becomes a hollow shaft and now delivers it's torque to the rear, to the center differential. Onlythrough a second shaft, within the hollow shaft, is the power flow given from the front (left) bevel-gear of the center differential, to the front axle. The torque from the rear (right) bevel-gear is transferred to the rear axle through the cardan shaft.This simple method of transferring power to the front, is only used in manual gearboxes. In the case of an automatic gear box, there is - as with all-wheel drive from a standard drive train - a shaft running past the gear box to the front.

Important

Although the illustrations seen above show an all-wheel drive, they do not however, contain any limited-slip. Despite the all-wheel drive, there is no certainty, that traction will also be available when one wheel is in the air or on slippery black ice. 05/10