GF27.60-P-3024ACM Working/Lubrication/Shift Pressure, Function

GF27.60-P-3024ACM Working/lubrication/shift pressure, function
- TRANSMISSION 722.643/649
- refinement package
- as of model year 09


Function requirements for working/lubrication/shift pressure, general
^ Circuit 87 ON
^ Circuit 61 (engine running)

Working/lubrication/shift pressure, general
The oil pressures are separated into:
^ Working pressure
^ Lubricating pressure
^ Shift pressure

Working pressures
The working pressure supplies pressure to the hydraulic control and transmission elements.

The working pressure is the highest hydraulic pressure in the complete hydraulic system. The level of working pressure is regulated at the working pressure regulating valve depending on current load and the gear engaged. All other pressures required for the transmission control are derived from the working pressure.

Lubricating pressures
At the working pressure regulating valve excess oil is diverted to the lubrication pressure regulating valve and from there used in a regulated manner for lubrication and cooling of mechanical transmission parts and the torque converter.

In addition the pressure in the torque converter is limited via the lubrication pressure.

Shift pressures
The level of shift pressure is determined by the shift pressure control solenoid valve (Y3/6y2) and shift pressure regulating valve. It regulates the pressure in the engaging actuator during the shift phase. Together with the modulating pressure the shift pressure determines the pressure release regulated by the overlap regulating valve at the disengaging actuator and initializes 2nd gear in limp-home mode.