HYDRAULIC CONTROL UNIT
Working Pressure Regulating Valve (Operating Pressure)
The working pressure (p-A) is regulated at the working
pressure regulating valve (4) in relation to load (mod-
ulating pressure) and gear (K1 or K2 pressure). The
spring in the working pressure regulating valve sets a
minimum pressure level (basic pressure).
Torque Converter Lockup Clutch Regulating Valve
The torque converter lockup clutch regulating valve (6)
regulates the torque converter lock-up clutch working
pressure in relation to the torque converter clutch con-
trol pressure. According to the size of the working
pressure, the torque converter lockup clutch is either
Engaged, Disengaged, or Slipping. When the regulat-
ing valve (6) is in the lower position, lubricating oil
flows through the torque converter and oil cooler (8)
into the transmission (torque converter lockup clutch
unpressurized). In its regulating position (slipping,
torque converter lockup clutch pressurized), a reduced
volume of lubricating oil flows through the annular
passage (7) bypassing the torque converter and pass-
ing direct through the oil cooler into the transmission.
The rest of the lubricating oil is directed via the throttle
“a” into the torque converter in order to cool the torque
converter lockup clutch.
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AUTOMATIC - NAG1 SERVICE INFORMATION
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