by Mike Parker
The purpose of the transmission in a car is to transfer the power created by the engine to the wheels through a driveshaft or axle shafts. Different gears in the transmission allow different levels of torque to be applied to the wheels depending on the speed at which the vehicle is traveling. To change the torque level, the transmission gears must be shifted manually or automatically. At first, all transmissions were manual.
French inventors Louis-Rene Panhard and Emile Levassor are credited with developing the first modern manual transmission. They demonstrated their three-speed transmission in 1894 and the basic design remains the starting point for most contemporary manual transmissions.
Panhard and Levassor used a chain drive in their original transmission. In 1898, automaker Louis Renault used its basic design, but replaced the drive chain with a driveshaft and added a differential axle for the rear wheels to improve the performance of the manual transmission.
At the beginning of the 20th century, most cars made in the United States featured an unsynchronized manual transmission based on the Panhard / Levassor / Renault design. The next big innovation occurred in 1928 when Cadillac introduced the synchromesh manual transmission, which significantly reduced gear grinding and made shifting easier and smoother.
Manual transmissions were the standard in most vehicles during the first half of the 20th century, but automatic transmissions were being developed as early as 1904. General Motors introduced the clutchless automatic transmission under the name Hydra-Matic in 1938, but The first true fully automatic transmission did not appear until 1948 with the Buick Dynaflow transmission.
Americans tend to prefer automatic transmission in their vehicles, whereas Western Europe is, and is expected to remain, the largest market for manual transmissions until 2014. Eastern Europe and Asia are also large markets for manual transmissions, although Japan seems to be adopting more automatic transmissions. transmissions. In the United States, more manual transmissions are found in the northern states than in the southern states. Manual transmissions are supposed to give better control on icy roads and are therefore most useful in the north where the winters are harsher.