The Charge of the oil force in the lock-up clutch is done by means of two valves: the relay valve plus the signal valve. In this sort of arrangement the sign valve controls the force on one side from the relay valve, which controls the stress inside the lock-up clutch. https://torqueconverterclutch65296.blogthisbiz.com/41098270/helping-the-others-realize-the-advantages-of-torque-converter-clutch