Function of power flow in reverse gear, function of program selection "S" - GF27.10-P-3017SXA

TRANSMISSION 722.6 in MODEL 204.0, 216, 221 up to Model Year 8 

Fig 1: Identifying Sectional View Of Power Flow In Reverse Gear (S Function)

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Power Flow Diagram In Reverse Gear

Courtesy of MERCEDES-BENZ USA

Principle of power transmission in reverse gear with program selection "S" 

Via the drive shaft (1) and involving all 3 planetary gear sets the torque coming out of the torque converter is increased and transmitted to the output shaft (5) with an opposite direction of rotation.

The following are not engaged:

• Multi-disk brake B2 (22)
• Freewheel F2 (28)
• Multi-disk clutch K1 (24)

Front planetary gear set 

The input shaft (1) drives the internal gear (29/4). In drive mode the sun gear (29/1) is supported via the locked freewheel F1 (27) and in overrun mode via the engaged multi-disk brake B1 (21) on the housing. The planetary gears (29/2) revolve around the stationary sun gear (29/1) and ensure that torque is increased when power is transmitted from the ring gear (29/4) to the planet carrier (29/3). The planet carrier (29/3) moves at reduced speed in the direction of rotation of the engine.

Rear planetary gear set 

The engaged multi-disk brake B3 (23) means that the planet carrier (31/3) is held at the housing. The ring gear (31/4) rotates at reduced speed due to the mechanical connection to the planet carrier (29/3). The planet gears (31/2) turn between the ring gear (31/4) and the sun gear (31/1). The held planet carrier (31/3) means that a reversal of direction ensues so that the sun gear (31/1) turns against the engine direction of rotation.

Center planetary gear set 

The ring gear (30/4) is held via the mechanical connection to the planet carrier (31/3) of the multi-disk brake B3 (23) on the housing. The sun gear (30/1) rotates backwards due to the engaged multi-disk clutch K3 (26). The planetary gears (30/2) revolve around the stationary sun gear (30/4) and ensure that torque is increased when power is transmitted from the ring gear (30/1) to the planet carrier (30/3). The output shaft (5) connected to the planet carrier (30/3) rotates at reduced speed opposite to the direction of rotation of the engine.