Automatic Transmission (AT) Design

The converter housing and transmission housing consist of a light metal alloy. These are bolted together and centered via the outer multiple-disc carrier of multiple-disc brake B1. A coated intermediate plate serves as the seal. The oil pump and the outer multiple-disc carrier of multiple-disc brake B1 are bolted to the converter housing. The mechanical section consists of the input shaft, output shaft, a sun gear shaft and three planetary gear sets which are connected together. The planetary gear sets each have tour planet gears on transmissions for powerful engines while on less powerful engines the front and rear planetary set is equipped with three planet gears. The stator shaft is pressed fitted and prevented from-turning by splines.

The electrohydraulic control unit is screwed onto the transmission housing from underneath. The closure is formed by a sheet-steel oil pan.

The oil pressure for the converter lock-up clutch and clutch K2 is supplied through bores in the input shaft. The oil pressure to clutch K3 is supplied through the output shaft. The lubricating oil is supplied and distributed through additional bores in both shafts. All bearing points of the gear sets, freewheels and actuators are supplied with lubricating oil. The parking lock gear and output flange are connected to the output shaft via splines.

The freewheels F1 and F2 serve to optimize shifts. The front freewheel is supported on the stator shaft extension on the transmission side and, in the locking direction, connects the sun gear of the front planetary gear set with the transmission housing. The rear freewheel connects in locking direction the sun gear of the center planetary gear set with the sun gear of the rear planetary gear set.

The electrohydraulic control unit is comprised of the light-alloy shift plate for the hydraulic control and an electrical control unit. The electrical control unit consists of a plastic supporting body in which the electrical components are combined. The supporting body is mounted on the shift plate and screwed to it. Printed conductors inserted in the supporting body connect the electrical components and a plug-in connector. The connection to the wiring harness on the vehicle side and the transmission control module (electronic transmission control) is made via this 13-pin plug-in connector with a bayonet lock.