How the Present-Day Automatic Transmission Came to Be
Automatic transmissions have become important in modern-day automobiles, but there is a lengthy history behind them! Continue reading to learn more about how these transmissions have evolved!
Automatic Safety Transmission
In 1937 General Motors started offering a semi-automatic transmission, which was called the "Automatic Safety Transmission," or AST. This transmission had a friction clutch, four forward speeds and a planetary gear set. Oldsmobile and Cadillac used the AST in a few models in the late 1930s, and Buick made it available for the Buick Special for a short time. However, the AST was short lived because potential vehicle purchasers didn't think that having this in a vehicle would make it run all the better.
$57 Hydra-Matic Transmissions
By 1941 the $57 Hydra-Matic transmission was a popular transmission option for prospective car buyers. This is because it didn't require a driver to use a clutch pedal to operate it. Unlike today's transmissions, it did not have a "Park" mode. Instead, when a driver went into Reverse and shut their engine off, a parking prawl activated itself to keep the car from rolling while parked. This transmission was basically a redesigned AST, and it ended up being mass-produced and used commercially. Later assembled automatic transmissions were built with the $57 Hydra-Matic transmission as the foundation.
By 1941 about 40% of all Oldsmobile cars came with the $57 Hydra-Matic Transmission. By 1942, when car manufacturing plants stopped making passenger vehicles for a while to focus on building wartime machinery, over 200,000 Hydra-Matic automatic transmissions had been sold. The reason behind the "$57" in the transmission's name is because it started off as a $57 option for the 1940 Oldsmobile.
Automatic transmissions with overdrive were being put in vehicles beginning in the late 1970s and early 1980s. The new transmissions with overdrive gave drivers four or more forward gears. Many automakers offered overdrive-equipped automatic transmissions by the early 1980s.
Number of Available Gears for Transmissions
In the 1980s many cars had four-speed automatic transmissions, however, many vehicles' gearboxes come with five or six gears today. In the mid to late 2000s vehicle manufacturers began offering their transmissions with seven, eight and even nine-speed automatic configurations.
New electronically controlled transmissions offer many capabilities. They're controlled by a computer that every few milliseconds can gather and process tons of information. Electronically controlled transmissions allow for extremely precise shifts. They can also shift according to the terrain. For example, when one is driving through a mountainous terrain some electronically controlled automatic transmissions can control speed when going downhill by automatically downshifting. The team at CDJR Mopar Parts can provide you with more information on these types of transmissions!
Many, many vehicles now have automatic transmissions, and these transmissions are so convenient because they automatically change the gear ratios as the driver moves. There are still manual transmissions available, but generally now when a teenager learns to drive they're using an automatic and learn to drive a manual later if they absolutely need to learn.
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