The very first automatic transmission to employ a torque converter (in place of a fluid coupling) was the Buick Dynaflow, which was introduced for that 1948 design year. In standard driving, the Dynaflow used only the major gear, relying on the torque multiplication on the torque convertor at lower speeds. https://brookswcdbz.free-blogz.com/81395049/top-guidelines-of-gearbox-auto