The torque converter clutch solenoid is usually energised (trapped on) which interprets into the torque converter being always locked. Slippage consumes ability over the coupling phase. Locking the converter shell to your turbine shaft prevents this slippage from happening. The matching curve from the turbine blades will help to properly https://torque-converter-clutch42963.thezenweb.com/the-basic-principles-of-torque-converter-clutch-72019684