By mechanically linking the turbine for the pump, it results in a ‘lock-up’ ailment, fundamentally transforming the fluid coupling right into a rigid coupling, akin to the locked manual transmission clutch. The LuK converter clutch is very active and could use in any gear but normally from 2nd on up. https://tysongouyy.blogdon.net/facts-about-torque-converter-clutch-revealed-50311127