The 1st automatic transmission to work with a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was launched for the 1948 product yr. In normal driving, the Dynaflow applied only the top equipment, depending on the torque multiplication in the torque convertor at lower speeds. https://emiliojorsr.myparisblog.com/34706986/the-best-side-of-gearbox-auto