A Closer Look at the Components of an Automatic Transmission

Automotive Transmission

Have you ever looked inside of an automatic transmission? Within an automatic transmission you’ll find dozens of parts that work together to transfer power from the engine to the wheels. Before you visit our car repair shop for transmission maintenance or repair , you might enjoy reading this article, which provides an overview of the components inside of an automatic transmission.


Automatic transmissions have planetary gear sets that consist of the sun gear, planet gears, and ring gear. These gears move and interact together, which allows the car to attain a range of forward and reverse speeds.


The clutch pack inside of an automatic transmission is comprised of several discs inside of a drum. To facilitate gear shifts in an automatic transmission, a piston inside the drum squeezes the clutch pack together using oil pressure, which locks the components of the clutch pack together.


Essentially bands of steel with frictional material, the bands of an automatic transmission will tighten under pressure. When this happens, the bands are able to tighten around the clutch pack drum and prevent it from turning.

Torque Convertor

Located between the engine and the gears, the torque convertor prevents the car from stalling while idling by keeping the transmission disengaged from the engine. When you press on the gas pedal, more fluid goes into the torque convertor, which allows more power to flow from the engine to the transmission.

Valve Body

Known as the brains of the transmission, and located near the bottom of the assembly, the valve body is filled with hydraulic fluid that travel to the valves, which engages the clutch pack or band in order to shift gears.

If you believe your automatic transmission needs service or repair, come to Murray’s Auto Clinics in Silver Springs, MD. We have experience working with transmissions, brakes, engines, and all other important parts of your vehicle. Visit our website to learn more about the car repair and maintenance services we offer, and call us at (240) 450-2712 for more information.