Shift From 1 To 2, Function - GF27.60-D-4013H

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 1st gear engaged 

Courtesy of MERCEDES-BENZ USA

Shift phase 

Courtesy of MERCEDES-BENZ USA

2nd gear engaged 

Courtesy of MERCEDES-BENZ USA

Aim 

Connect multidisk clutch K1, switch off multidisk brake B1

Function 

1st gear engaged 

The end face of the 1-2/4-5 command valve is held unpressurized via the 1-2- and 4-5 shift solenoid valve. Working pressure at the multidisk brake is applied via the 1-2/4-5 holding pressure valve B1. The multidisk clutch K1 is unpressurized.

Shift phase 

Via the 1-2 and 4-5 shift solenoid valve the shift valve pressure is switched so that it acts on the end face of the 1-2/4-5 command valve. As a result the 1-2/4-5 command valve is displaced and the shift pressure, coming from the 1-2/4-5 shift pressure shift valve is lead via the 1-2/4-5 command valve to the multidisk clutch K1. Overlap pressure is applied simultaneously to the multidisk brake B1 from the 1-2/4-5 overlap regulating valve.

The pressure from the multidisk brake acting on the end face of the 1-2/4-5 shift pressure shift valve is superseded by the working pressure B1. The increasing shift pressure at the multidisk clutch K1 acts on the annular surface on the 1-2/4-5 overlap regulating valve and reduces the overlap pressure regulated by the overlap regulating valve 1-2/4-5. This switches over at a corresponding pressure level at the 1-2/4-5 holding pressure shift valve.

2nd gear engaged 

Once the gear change is complete, pressure on the end face of the 1-5 command valve is reduced via the 1-2- and 4-5 shift solenoid valve 2/4- and this is pushed into the basic position. Working pressure now reaches the multidisk clutch via the 1-2/4-5 holding pressure shift valve and the command valve 1-2/4-5 K1. The multidisk brake B1 is switched off (unpressurized). The spring in the shift pressure shift valve 1-2/4-5 pushes this into the basic position.