The torque converter clutch will come into motion to mitigate the inherent inefficiency from the fluid coupling at higher speeds. Torque converters can be found in Virtually all vehicles with automatic transmissions. This is probably certainly one of the reasons why you have heard about lots of failed torque converters. https://torque-converter-clutch11863.59bloggers.com/34697096/the-2-minute-rule-for-torque-converter-clutch