Torque converter lockup clutch, component description - GF27.20-P-5102CWQ

TRANSMISSION 722.9 in MODEL 204.0 up to Model Year 8

Fig 1: Identifying Torque Converter Lockup Clutch Location

Courtesy of MERCEDES-BENZ USA

Location

The torque converter lockup clutch is integrated in the torque converter.

Task

The torque converter lockup clutch minimizes the power losses of the torque converter by reducing converter slip. The engine speed reduces as a result and the efficiency of the transmission is improved.

Design

The external plate carrier is connected to the impeller via the converter housing. The internal plate carrier is connected to the turbine wheel.

Fig 2: Identifying Torque Converter Lockup Clutch Components

Courtesy of MERCEDES-BENZ USA

Function

When actuated by the fully integrated transmission control unit (Y3/8n4), oil pressure controlled by the torque converter lockup clutch control solenoid valve (Y3/8y8) is directed through the input shaft to the pressure chamber behind the piston. The piston presses the clutch pack together and thus enables direct torque transmission between the impeller and turbine wheel.

The torque converter lockup clutch is connected in all gears depending on engine speed and engine load. The torsional damper damps the vibrations coming from the engine. This improves comfort for the driver and saves wear and tear on the mechanical components of the transmission.