Working/lubrication/shift pressure, function - GF27.60-P-3024AHZ

TRANSMISSION 722.902 /903 /904 /906 /907 in MODEL 164.1 as of Model Year 09 /Modification year 08 Model refinement package 

TRANSMISSION 722.902 /903 /904 in MODEL 164.8 as of Model Year 09 /Modification Year 08 

TRANSMISSION 722.902 /904 /906 /999 in MODEL 251.0 as of Model Year 09 /Modification year 08 

TRANSMISSION 722.902 /904 /906 /999 in MODEL 251.1 as of Model Year 09 /Modification year 08 

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 pressure 

The oil pressure produced by the oil pump is converted into working pressure by the working pressure regulating valve. The level of working pressure depends on the position of the regulating valve and therefore on its geometry. The position of the working pressure regulating valve is influenced by the working pressure control solenoid valve (VGS) (Y3/8y1) in a manner which is dependent on load and gear. All other pressures required for the transmission control are derived from the working pressure.

Lubricating pressure 

Excess oil is diverted to the lubrication pressure regulating valve at the working pressure regulating valve and from there used in a regulated manner for lubricating and cooling the mechanical transmission parts and torque converter. In addition the pressure in the torque converter is limited via the lubrication pressure.

Shift pressure 

The shift pressure (pressure in the multi-disk clutch or in multi-disk brake) is derived from the working pressure. The respective control solenoid valve influences the position of the associated regulating valve. In turn the position influences the pressure prevailing in the multi-disk brake or in multi-disk clutch. The pressure thus depends on the geometry of the respective regulating valve.