Acura 3.5 RL Manual page 502

Description
Lock-up System
Lock-up Clutch
1. Operation (clutch on)
With the lock-up clutch on, the fluid in the chamber between the torque converter cover and the lock-up piston is drained
off, and the converter fluid exerts pressure through the piston against the torque converter cover. As a result, the converter
turbine is locked to the converter cover. The effect is to bypass the converter, thereby placing the vehicle in direct drive.
2. Operation (clutch off)
With the lock-up clutch off, the fluid flows in the reverse of CLUTCH ON. As a result, the lock-up piston moves away from
the converter cover, and the torque converter lock-up is released.
LOCK-UP PISTON
TORQUE CONVERTER
COVER
TORQUE CONVERTER
COVER
DAMPER SPRING
TURBINE
MAINSHAFT