The initial automatic transmission to use a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was introduced for that 1948 model calendar year. In usual driving, the Dynaflow utilised just the prime gear, relying on the torque multiplication from the torque convertor at decreased speeds. https://gearbox-auto24444.ja-blog.com/33870629/the-ultimate-guide-to-gearbox-auto