The torque converter clutch solenoid is often energised (stuck on) which translates into the torque converter remaining generally locked. To counter this influence, some automobiles Possess a torque converter having a lockup clutch. If the two halves of your torque converter get up to the mark, this clutch locks them https://torqueconverterclutch80009.eedblog.com/34080282/rumored-buzz-on-torque-converter-clutch