The Evolution of the Automatic Transmission
Many, many vehicles now come with automatic transmissions, and these transmissions are so great because they automatically change the gear ratios as the driver moves. There are still manual transmissions out there, but generally now when a teenager learns to drive they are using an automatic and learn to drive a manual later if the need to know how to use one presents itself.
Automatic transmissions have become a very important part of modern-day automobiles, but there is a lengthy history behind them! Keep reading to learn more about how automatic transmissions have evolved into their modern contraptions!
First Known Invention
It was in 1921 that Alfred Horner Munro of Saskatchewan, Canada, invented a form of the automatic transmission. It was patented in Canada in 1923, in the United Kingdom in 1924 and in the United States in 1927.
Automatic Safety Transmission
In 1937 General Motors introduced a semi-automatic transmission, which was called the “Automatic Safety Transmission,” or AST. The AST had a friction clutch, a planetary gear set and four forward speeds. Oldsmobile and Cadillac used the AST in a few models in the late 1930s, and Buick offered it for their Buick Special for a short time. However, the AST was short lived because prospective vehicle purchasers weren’t convinced that having this in a vehicle would make it run all the better.
$57 Hydra-Matic Transmission
By 1941 the $57 Hydra-Matic transmission was a very popular transmission option for prospective vehicle buyers. This is because it didn’t require a driver to use a clutch pedal to operate it. It was essentially a redesigned AST, and it ended up being mass-produced and commercially-used. Later built automatic transmissions were assembled with the $57 Hydra-Matic transmission as the foundation. The reason behind the “$57” in the transmission’s name is because it was initially a $57 option for the 1940 Oldsmobile.
By 1941 about 40% of all Oldsmobile cars had the $57 Hydra-Matic Transmission in them. By 1942, when, car manufacturing plants stopped making passenger vehicles for a bit to focus on building wartime machinery, over 200,000 Hydra-Matic automatic transmissions had been sold.
Transmissions with Overdrive
Automatic transmissions with overdrive were being put in vehicles starting in the late 1970s and early 1980s. These new transmissions with overdrive gave drivers four or more forward gears to use. The majority of automakers offered overdrive-equipped automatic transmissions by the early 1980s.
Number of Gears Available for Automatic Transmissions
In the 1980s many vehicles had four-speed automatic transmissions, however, nowadays many vehicles’ gearboxes come with five or six forward gears. In the mid to late 2000s many vehicle manufacturers started offering their products with seven, eight and even nine-speed automatic transmissions.
New electronically controlled transmissions have a number of capabilities. They are controlled by a computer that every few milliseconds can gather and process large amounts of information. Electronically controlled transmissions allow for very precise shifts.
The folks at CDJR Mopar Parts can provide you with more information on how automatic transmissions came to be!
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