Fluid Coupling: It permits the motor to run independently of the transmission, Hence the vehicle can end with no stalling the engine. This fluid coupling lets the engine to carry on working even if the auto is stationary, avoiding it from stalling and boosting torque when accelerating from the end. https://edwinmqrrp.activosblog.com/32969933/5-simple-statements-about-torque-converter-clutch-explained