How Hydra-Matic Transmission Changed the Automotive Industry

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Even if you’ve never heard of Hydra-Matic transmission, chances are, you’ve used the technology. Developed and described in Earl Thompson’s patent disclosures as far back as 1934, it changed the automotive industry. If you can’t drive a stick shift, you probably appreciate the ability to enjoy a fully-automatic transmission, and the Hydra-Matic marked the shift away from the clutch and the beginning of new freedom for drivers around the world.

Evolution of the Hydra-Matic Transmission


As with any innovation, consumer feedback allows manufacturers to make products better and better. Especially during its early years, the Hydra-Matic transmission underwent a variety of minor yet important changes:

  • Revisions in gearing and oil pump designs
  • 1951- Introduction of a hydraulically-operated cone clutch to engage the new reverse planetary gearset
  • 1952- Dual-Range Hydra-Matic that enabled two drive ranges to allow drivers to more effectively tackle hilly terrain and highway passing
  • 1952- Expansion in the production of Hydra-Matic transmission units to 700,000 annually through licensing agreement
  • 1953- Retooling of the vast Willow Run factory for Hydra-Matic production following devastation of the Detroit Transmission plant in Livonia
  • 1956- Introduction of the second-generation Hydra-Matic in response to consumer complaints regarding harsh shifts

A Timeline of Hydra-Matic Brainpower


The changes made that allowed the Hydr-Matic the success it experienced was powered by a succession of innovative minds, each contributing unique and important details.

  • 1934-1940- Earl Thompson, who first described Hydra-Matic transmission in 1934, left GM in 1940 to start his own company.
  • 1940- O.K. Kelley becomes Thompson’s de facto successor and goes on to play an integral role in the future of GM’s transmission development efforts.
  • 1940-1955- Oldsmobile general manager Charles McCuen promoted to vice president of engineering following Thompson’s resignation. He retired early following a debilitating accident.
  • 1951-1969- Hydra-Matic early developer Harold Metzel serves as Oldsmobile’s chief engineer.

Thompson and others were recognized for their efforts in the technology that changed the way the world moved. In 1963, he was awarded the Elmer A. Sperry Award. He and other members of his team also received Citations for their contributions to the original Hydrao-Matic. They included Beck, Carnegie, Herndon, Kelley and Rosenberger.

Hydra-Matic Transmission: Shaping Powertrain Development

From Oldsmobile and Cadillac to Pontiac, Buick, Chevy and more, the Hydra-Matic concept spread like wildfire due largely to its positive reception in the market. It allowed drivers to shift faster, made for easier maintenance and took a large degree of stress out of the equation when getting from Point A to Point B.

It’s easy to take everyday conveniences for granted. The next time you shift into drive and seamlessly accelerate, take a moment to think about the many ways Hydra-Matic transmission shaped powertrain development over the years. Although it wasn’t the first automatic transmission, it was the first that made a real impact in the industry. It set the precedents necessary to shape future innovations for the next 60 years.

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