The Charge of the oil force during the lock-up clutch is done by two valves: the relay valve and also the sign valve. In this type of arrangement the signal valve controls the tension on a person side in the relay valve, which controls the force inside the lock-up clutch. https://torqueconverterclutch09527.onesmablog.com/the-best-side-of-torque-converter-clutch-74887479