The primary automatic transmission to use a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was introduced for that 1948 model 12 months. In usual driving, the Dynaflow utilized just the prime gear, counting on the torque multiplication from the torque convertor at reduced speeds. https://gearboxauto97529.spintheblog.com/34183735/indicators-on-gearbox-auto-you-should-know