Since the turbine pace lags continuously at the rear of the impeller (pump) pace, the pace ratio is less than one. Therefore You can find friction inside the transmission fluid which leads to electrical power losses. The torque converter clutch solves this by locking the turbine towards the converter’s housing, https://trentonvnamy.theblogfairy.com/33147348/indicators-on-torque-converter-clutch-you-should-know