HydraMaticSelectorThe automatic transmission has seen a rich history dating back to the 1930s when General Motors engineered the first prototype for its Oldsmobile brand. It wasn’t until 1940 that Earl Thompson’s vision was forged into solid reality with the advent of the first fully-functional model.

The Hydra-Matic

The first consumer vehicle with an automatic transmission was introduced under the Oldsmobile brand with the trademark of the «Hydra-Matic» transmission. While speculation as to the date of the actual first concept of the automatic transmission exists, it is clear that Earl Thompson was developing the technology as early as the 1920s as an improvement to the Synchro-Mesh Gearbox, also a product of his invention. the Hydra-Matic was the first mass-produced and successfully implemented automatic transmission model in the history of the automotive industry.

Early Innovations and Limitations

The distinction of an automatic transmission is its ability to passively select gear ratios without the aid of the driver engaging a clutch or manually changing gears.

Compared to today’s models, the original automatic transmission was very simple in its design and its implementation. The Hydra-Matic, for example, had four forward gears and reverse. There was no «park» setting like those common on today’s vehicles. In order to secure the vehicle, one had to first disengage the engine and then set the gears to reverse. Doing this safely locked the transmission and prevented the vehicle from rolling.

Building on a Good Idea

Many advancements would be part of the future of the Hydra-Matic. These advancements came in the form of minor yet beneficial changes until 1952 when the first major revision was developed. It was in that year that Kenneth Gage unveiled the «Dual-Range Hydra-Matic» in the 1952 Pontiac.

The breakthrough aspect of this new and improved model was the availability of two drive ranges. Along with the standard neutral, drive, low and reverse gears, the Dual-Range also featured a second range with settings D1, D2, D3 and S. The «S» stood for «super» and, in this range, would not shift out of third gear until the car reached an approximate speed of 70-72 MPH (112-118 KPH).

The position of the reverse gear in the Dual-Range accidentally led to the standard PRNDL pattern still used in today’s automatic transmissions. Numerous questions of safety arose out of claims that it was too easy for the driver to shift out of drive and into reverse in a vehicle with this transmission while the car was in motion.

The Automatic Transmission Today

Today’s automatic transmissions boast a much more robust functionality and are far easier for the driver to manage. However, that kind of convenience does come with a price. That price includes a much greater intricacy to its moving parts, the hydraulic controls and valve body and the need for professional servicing of components which were, at one time, more accessible to the consumer.