Mercedes-Benz ML320. Manual — part 189

Fig. 127: Power Flow In 4th Gear Function
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Principal of power transmission in 4th gear

The direct drive ratio of 4th gear (i = 1) means that there is no torque and speed conversion. Power is transferred
from the propeller shaft (1) to the input shaft (5) via three locked planetary gearsets (5). See Fig. 127.

The following are not engaged:



Front Multi-Disc Brake (B1)



Rear Multi-Disc Brake (B2)

2001 Mercedes-Benz ML320

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

me



Center Multi-Disc Brake (B3)



Freewheel F1



Freewheel F2

Front Planetary Gear Set

The planet carrier (V3) and sun gear (V1) are rigidly connected with each other via the engaged front multi-disc
clutch (K1). The planetary gearset is therefore blocked and turns as a closed unit at the input speed due to the
mechanical connection of the ring gear (V4) and propeller shaft.

Rear Planetary Gear Set

The center multi-disc clutch (K2) is engaged and transmits the input speed of the input shaft (1) to the planet
carrier (H3) via the hollow gear (M4). The ring gear (H4) turns in the same way as the planet carrier (H3) due to
the mechanical connection with the locked front planetary gearset. This planetary gearset is therefore locked
and turns as a closed unit.

Center Planetary Gear Set

The hollow gear (M4) rotates at input speed due to the engaged center multi-disc clutch (K2). The rear multi-
disc clutch (K3) connects the sun gears of the center planetary gear set (M1) and the rear planetary gear set
(H1). The planetary gearset is locked by the same speeds of the ring gear (M4) and the sun gear (M1) and it
turns as a closed unit.

Torque Converter, Location/Task/Design/Function

See TORQUE CONVERTER, LOCATION/TASK/DESIGN/FUNCTION.

Planetary Gear Set, Location/Task/Design/Function

See PLANETARY GEAR SET, LOCATION/TASK/DESIGN/FUNCTION.

Multi-Plate Clutch, Location/Task/Design/Function

See MULTI-PLATE CLUTCH, LOCATION/TASK/DESIGN/FUNCTION.

Power Flow In 5th Gear Function

2001 Mercedes-Benz ML320

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

me

Fig. 128: Power Flow In 5th Gear Function
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Principles of power transmission in 5th gear

Torque from the torque converter is increased via the propeller shaft (1) and all three planetary gearsets and
transferred to the output shaft (5). See Fig. 128.

The following are not engaged:



Rear Multi-Disc Brake (B2)

2001 Mercedes-Benz ML320

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

me



Center Multi-Disc Brake (B3)



Freewheel F2



Front Multi-Disc Clutch (K1)

Front Planetary Gear Set

The input shaft (1) drives the internal gear (V4). In the drive mode the sun gear (V1) is supported via the locked
freewheel (f1) and in overrun mode in the housing via the engaged front multi-disc brake (B1). The planet gears
(V2) roll over the fixed sun gear (V1) and provide an increase in torque between the internal gear (V4) and the
planet carrier (V3). The planet carrier (V3) moves at reduced speed in the direction of engine rotation.

Rear Planetary Gear Set

The center multi-disc clutch (K2) is engaged and transmits the input speed of the input shaft (1) to the planet
carrier (H3) via the hollow gear (M4). The internal gear (H4) turns at a reduced speed because of its mechanical
connection to the front planet carrier (V3). The planet gears (H2) turn between the ring gear (H4) and the sun
gear (H1). The sun gear (H1) moves at increased speed in the direction of engine rotation.

Center Planetary Gear Set

The hollow gear (M4) rotates at input speed due to the engaged center multi-disc clutch (K2). The rear multi-
disc clutch (K3) transmits a higher speed to the sun gear (M1) due to the connection to the sun gear (H1). The
planet gears (M2) turn between the ring gear (M4) and the sun gear (M1). The speed of the planet carrier (M3)
and the output shaft connected to the planet carrier (5) lies between that of the ring gear (M4) and the sun gear
(M1). This provides a step-up ratio.

Torque Converter, Location/Task/Design/Function

See TORQUE CONVERTER, LOCATION/TASK/DESIGN/FUNCTION.

Planetary Gear Set, Location/Task/Design/Function

See PLANETARY GEAR SET, LOCATION/TASK/DESIGN/FUNCTION. .

Multiple-Disc Brake, Location/Task/Design/Function

See MULTIPLE-DISC BRAKE, LOCATION/TASK/DESIGN/FUNCTION.

Multi-Plate Clutch, Location/Task/Design/Function

See MULTI-PLATE CLUTCH, LOCATION/TASK/DESIGN/FUNCTION.

Power Flow In Reverse, Function (Without Touch Shift)

2001 Mercedes-Benz ML320

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

me