Mercedes-Benz ML320. Service manual

Fig. 108: Selector Lever Positions
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

AUTOMATIC TRANSMISSION, FUNCTION

Transmission With Touch Shift 722.6 In Model 163

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 gearsets. The 5th gear is designed as a low-rev gear
with an overdrive ratio.

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.

The oil pump as well as the external plate carrier of the front multi-disk brake are bolted to the torque converter
housing.

The mechanical part of the transmission 722.6 consists of a drive shaft, output shaft, a sun gear shaft and 3
planetary sets which are coupled to each other.

The electrohydraulic control unit is screwed onto the transmission housing from below. The end of the
transmission if formed by an oil pan made of sheet steel.

The oil pressure of the torque converter lockup clutch and center multi-disk clutch is supplied via bore holes in
the drive shaft. The oil pressure to the rear multi-disk clutch is supplied via the output shaft. The lubricating oil
is supplied and distributed by additional bore holes in both shafts. Oil is supplied to all bearing points of the
gearsets as well as to the freewheels and shifting elements.

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

Basically transmission 722.6 with electronic control offers the following advantages:



Reduced fuel consumption.



Greater ease of shifting.



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 multi-disk brake at the front. A coated intermediate
panel seals the two components.

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

2001 Mercedes-Benz ML320

1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662

Mercedes-Benz ML320. Service manual - part 181