The Borg-Warner four-speed transmission played a key role in launching the Motor City’s high-performance movement of the sixties.

When the Borg-Warner T-10 was introduced in 1957, four-speed transmissions were hardly an innovation. They were nearly as old as the auto industry, and in the 1950s all proper sports cars had to have one. Corvette engineer Zora Arkus-Dontov was keenly aware of that fact, saddled as he was with the Chevy three-speed manual box.

Considered good enough for American cars and drivers, three-speeds were universal equipment on the Detroit passenger cars of the ’50s, and there were no four-speed gearboxes suitable for performance applications in the General Motors supply chain. Working with GM engineering, Borg-Warner of Muncie, Indiana stepped up with the T-10 four-speed transmission, which became available on the Corvette on  May 1, 1957 as a $188 option.

The T-10 was actually a clever adaptation of Borg-Warner’s T-85 three-speed manual transmission. The reverse gear and idler were moved out of the main housing and relocated in the extension or tailshaft housing, and a direct fourth gear was located where reverse had been (above). All four forward speeds were synchonized, and the package fit neatly in the same physical space as a standard three-speed.

In the initial ’57 Corvette application, the closely-spaced gear ratios were: 2.20:1 (first), 1.66:1 (second), 1.31 (third), 1.00:1 (fourth) but over the T-10’s long production life, a number of close and wide-ratio gearsets were produced. In a 1957 road test of the Corvette, Road & Track magazine reported that the new four-speed “shifted beautifully, with an easy, short throw. It is virtually impossible to clash and is also much quieter than the 3-speed box.”

This three-speed/four-speed adaptation had actually been conceived and patented by General Motors years earlier, but Borg-Warner (now BorgWarner), a veteran transmission supplier, won the production contract. In Motor City legend, one story goes that the GM manufacturing brass decided that the production volume would be so low that it wasn’t worth the General’s time, so the job was shipped out. If the story is true, they didn’t foresee that in just a few short years, there would be an explosion of demand for four-speed transmissions in the performance-car market.

Corvette had the exclusive on the four-speed until 1959, when iit became an option on Chevrolet and Pontiac passenger cars as well. (The transmission was also available from GM dealers for $275 outright.) Ford made the T-10 available in the summer of ’61, over the counter at first, while Studebaker offered it on the 1961 Hawk. For 1963, Chrysler jumped on T-10 bandwagon, followed by American Motors in 1966. The Borg-Warner four-speed was now offered on performance cars across the U.S. market. It was an essential component in the ’60s muscle car movement.

GM, Ford, and Chrysler all developed their own four-speed gearboxes in due time, but an updated version of the B-W  four-speed called the Super T-10 was used in GM performance applications through the early 1980s. While the four-speed manual was eventually eclipsed by five and six-speed gearboxes in production vehicles, in the hot rodding and classic musle car worlds the T-10 never went away. Richmond Gear still offers brand-new Super T-10 transmissions and service parts today.