Wet Clutch Control Pressure, Function - GF27.60-P-3027ANE

Transmission 725.085 in model 463 

Function requirements, general 

• Circuit 87 ON
• Engine running

Wet clutch control pressure 

The wet clutch solenoid (Y3/8y22) is actuated by the fully integrated transmission control unit (Y3/8n4) and it influences the lube oil pressure in the pressure chamber behind the clutch piston. The lubricating oil is routed by the drive shaft to the pressure chamber behind the piston. This compresses the clutch pack through the clutch piston so that engine torque can then be transferred. The wet clutch is connected in all gears depending on the engine speed and the engine load. If the wet clutch solenoid is not actuated by the fully integrated transmission control unit, a lubrication oil pressure is set in the wet clutch housing that then serves to open the clutch piston. The lubrication oil volume flow and a special geometry of the clutch linings ensure optimum cooling of the wet clutch. A specified valve pressure is calculated from the specified clutch torque by means of an inverted distance model of the wet clutch. A subordinate flow regulator sets the required valve flow at the wet clutch solenoid.