Although we take it for granted now, the automatic transmission was an incredible technological advancement when it was introduced all the way back in 1939. For the first time ever, you could just put the car in Drive and it would change gears for you! No clutch pedal to push, no shifter move around. It was a luxuriously simple option that made driving a piece of cake. And it was brought to you by that long-lost GM division; Oldsmobile.
What Transmission Do I Have?
Inventing the first automatic car transmission
In the late 30s, most Americans could still remember traveling by horse and buggy. So shifting gears in an automobile was an accepted alternative to sitting behind a farting horse. But General Motors’ new Hydra-Matic automatic transmission was an absolute game changer. When Oldsmobile introduced it for the 1940 model year, over 60,000 buyers chose the pricy option. They sold twice that many the following year, and 30% of Cadillac buyers opted for the Hydra-Matic transmission when it was added to their options sheet for 1941. Other GM divisions decided not to use the new automatic transmission for one reason or another. And Cadillac’s version was actually beefed up to handle the increased torque of their V-8 engines.
Back then, each General Motors division (Buick, Cadillac, Pontiac, Oldsmobile etc.) operated as independent companies. They didn’t share technology, or much of anything else for that matter. But occasionally, the overlords at GM would compel different divisions to work together towards a common goal. This work was done at General Motors’ centralized R&D department known as Research Laboratories, under the watchful eye of chief engineer Charles Kettering. Up to this point, numerous “non-manual” transmission concepts had been explored. However, the Hydra-Matic transmission was the only gearbox to offer true two pedal driving, thanks to an innovation known as the fluid coupling.
The reason you don’t have to shift gears yourself
The fluid coupling had actually been patented back in 1905, but the Daimler Double-Six was the first automotive application of this relatively simple power transfer device. It works like this; if you had two electric fans facing each other and only one of them were switched on, the one without power would still turn in the opposite direction due to the wind created by the one with power. Now put these two fans together in a round, doughnut shaped case, fill it with transmission fluid, attach one fan to the engines crankshaft, and the other to the transmission pump, and voilà! You have a fluid coupling.
Now if you’re a mechanical nerd, you’re probably saying “isn’t that called a torque converter?”. And you would be partially right. A torque converter is a fluid coupling. However, it can also multiply torque because it has a third element called a stator. If you want to geek out on all things torque converter related, check these out:
How does a torque converter clutch work?
How do I know if my TCC solenoid is bad?
What Is Torque Converter Stall Speed?
How Performance Torque Converters Work
How Racing Torque Converters Work
World War II hits
The United States officially entered World War II after the attack on Pearl Harbor. Shortly after, US auto production ceased in 1942 and their production lines were converted to wartime use. Interestingly, the HydraMatic transmission would find its way onto the battlefield inside a number of different tanks and other heavy duty military vehicles. As you might imagine, there weren’t many young recruits with a lot of experience driving a tank. So the military worked7 with Cadillac to fit several different types of tanks with Cadillac V8 engines and Hydra-Matic transmissions. This made them infinitely more powerful and easy to drive, which gave the Allies a significant advantage in the unfamiliar European theater.
What Transmission Do I Have?
When Johnny comes marching home again, hurrah!
As automobile production got back underway, the 4-speed automatic HydraMatic transmission became the must-have feature demanded by the car starved public. Not only did other GM divisions finally decide to offer the gearbox in their vehicles, other car manufacturers (including Lincoln) bought the revolutionary transmission from GM. So while Oldsmobile may not have single handedly invented the automatic transmission, they had the most to do with its development which got them the right to bring it to market first.
