The primary automatic transmission to use a torque converter (rather than a fluid coupling) was the Buick Dynaflow, which was released for your 1948 design calendar year. In ordinary driving, the Dynaflow used only the top rated equipment, relying on the torque multiplication with the torque convertor at reduced speeds. https://gearbox-auto19528.fare-blog.com/34295412/gearbox-auto-for-dummies