Automatic Transmission (At), Function - GF27.10-D-0001H

Transmission 722.6 in MODEL 906.111/113/131/133/135/153/155/211/213/231/233/235/253/255/611/613/631/633/635/637/653/655/657/711/713/731/733/735 

Transmission 722.6 is an electronically controlled 5-speed transmission with a lockup clutch in the torque converter.

The ratios for the gear stages are achieved by 3 planetary gear sets. The 5th gear is designed with a step-up ratio as an overdrive. Shifting is initiated electronically. The gears are shifted by the corresponding combination of 3 hydraulically actuated multi-disk brakes, 3 hydraulically actuated multi-disk clutches and 2 mechanical freewheels.

Basically transmission 722.6 with electronic control offers the following advantages:

• Reduced fuel consumption
• Improved shift comfort
• Favorable spacing by 5 gears
• Long service life and high reliability
• Low maintenance costs

The torque converter housing and transmission housing consist of a light-metal alloy. Both housings are bolted together and are centered via the external plate carrier of the multidisk brake B1. A coated intermediate panel seals the two components.

The oil pump as well as the external plate carrier of the multidisk brake are bolted to the converter housing B1.

The mechanical part of the transmission 722.6 consists of input shaft, output shaft, a sun gear shaft and 3 planetary gear sets which are coupled together.

The electrohydraulic control unit is screwed onto the transmission housing from below. A sheet steel oil pan forms the closure.

The oil pressure for the torque converter lockup clutch and multidisk clutch is supplied through holes in the input shaft K2. The oil pressure to the multidisk clutch K3 is lead through the output shaft. The lubricating oil is supplied and distributed by additional bore holes in both shafts. All bearing points of the gear sets as well as freewheels and shift elements are supplied with lubricating oil.

The parking lock gear and drive flange are connected to the output shaft by gearing.

Freewheels F1 and F2 optimize shifting. The front freewheel is supported on the extension of the stator shaft at the transmission end F1 and connects the sun gear of the front planetary gear set with the transmission housing in the locking direction.

The rear freewheel F2 connects the sun gear of the center planetary gear set with the sun gear of the rear planetary gear set in the blocking direction.

The electrohydraulic control unit is comprised of a light alloy shift plate for the hydraulic control and an electric control unit (Y3/6). The electrical control unit consists of a supporting body made of plastic in which the electrical components are combined. The supporting body is mounted on the shift plate and is screwed to it. Conductor tracks which are laid in the supporting body make the connection between the electrical components and a 13-pin plug socket.