Evolution of the T56
BorgWarner designed the T-5 5-speed transmission that became one of the largest by volume of production. Using a very simple single-rail shift mechanism, the T5 was lightweight, came with a 5th-gear overdrive to add to fuel economy, and had a torque rating useable in engines of the period. The first T5 models used brass synchronizer rings and straight roller bearings to support the countershaft. BorgWarner refined the design and created “The World Class T5,” which used synchro rings lined with the same kind of paper material used in automatic transmissions, and went to tapered roller bearings for the gear train. The weak point of the T5 was its small size, which was easy to package in the diverse models of cars that used it, but with such a small centerline between the input and the countershaft, torque was limited to a high of 330 lb.-ft.