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What Does the Transmission Do?

What is a transmission and what are the different types of transmissions?

The transmission is one of the most important components of any motor vehicle. As the name implies, it controls and transmits power generated by the engine to the wheels. It controls the acceleration and deceleration of a motor vehicle smoothly, helping the engine to run at peak efficiency at all speeds.

Automatic Transmissions

Automatic transmissions come in several forms but operate in much the same way. The transmission includes a system of gears connected to the engine with a torque converter. When the driver places the vehicle in drive and pushes the accelerator, a system of bands and clutches is controlled by a hydraulic system to engage the appropriate gears as the vehicle’s speed increases. The process happens in reverse when the driver takes his or her foot off the accelerator and brakes. Some newer vehicles use an electronic control system to control the hydraulic system.

The other three settings on a vehicle with an automatic transmission are neutral, park, and reverse. When backing up the driver shifts into neutral, comes to a full stop, and then shifts into reverse. When parking, the driver will come to a full stop and then shift into park before turning off the engine. When starting a car, the driver will shift from park to drive or reverse as appropriate and then proceed.

Manual Transmissions

A manual transmission does everything that an automatic transmission does but with a lot more driver input. The driver presses the clutch pedal while using the stick shift to manually shift gears upwards as he or she accelerates and downwards as the vehicle decelerates. Few modern vehicles use a manual transmission because of the convenience of the automatic transmission. The advantages of using a stick include fuel savings and the idea that driving with one is “more fun.”


side cutout of an automatic automotive transmission

Maintaining a Transmission

A transmission should run smoothly so long as you maintain it properly for the life of a vehicle. The trick is to make sure that the transmission is filled with transmission fluid. The fluid should be changed periodically, according to the guidance in the vehicle’s owner’s manual. The manual should also indicate which type of transmission fluid is needed. While changing the transmission fluid is often considered a do-it-yourself task, it is best to take the vehicle to a shop where a skilled and experienced technician will perform the job as part of scheduled maintenance.

A sign that the transmission is failing is that it slips out of gear or is not changing gears at all when the vehicle accelerates. If such happens on the road, take the vehicle to a repair shop as soon as possible. As a measure of safety, pull over to the side of the road and call for a tow. Transmission failure can be catastrophic if it happens on the road.

Transmissions are filled with moving parts that even under the best of circumstances, wear out over time, depending on how often the vehicle is operated, especially during hot weather. Replacing or fixing a transmission can be an expensive job. After a certain point, it may be best to trade in the old vehicle for a new one.

Macs Radiator services Transmissions! Go to our Transmission Maintenance and Repairs page to learn more.




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