The initial automatic transmission to employ a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was introduced for that 1948 product calendar year. In usual driving, the Dynaflow used only the best gear, counting on the torque multiplication in the torque convertor at reduce speeds. https://gearboxauto75285.csublogs.com/41175360/the-basic-principles-of-gearbox-auto