Ever wonder exactly how a traditional manual transmission operates? Here’s an entertaining and educational look inside, courtesy of a 1936 Chevrolet film.

The venerable manual transmission is soon to become a historical artifact.  Fully-automatic transmissions, dual-clutch gearboxes, CVTs, and all-electric drivetrains are quickly rendering them passé. But dry your eyes, because there are plenty enough of the old-fashioned devices, both in collector cars and everyday drivers, to keep them on road for decades to come. There will always be an interesting application somewhere for your three-footed driving skills.

The title of this 1936 film, produced by the Jam Handy Organization for the Chevrolet division of General Motors, is appropriate enough: Spinning Levers.  Here, an elementary principle of machines—namely, force multiplication via the simple lever—is used to show how the transmission multiplies torque and varies speed  After all, a gearset is little more than a lever system, providing mechanical advantage in a rotating application. Also, at around the seven-minute mark in the production, there’s an excellent tutorial on gear synchronizers, a GM development first used on the 1928 Cadillac. As we always say here at Mac’s Motor City Garage, the old explanations are often the best explanations. Enjoy the movie.