Internal Parts of Automatic Transmissions

Your automatic transmission is comprised of various components that work together to change gears in your vehicle based upon your speed. If you begin to experience transmission problems, it is best to know the internal parts of automatic transmissions so you can diagnose accordingly.

Torque Converter

If you look in between your engine and the gear housing of your transmission, you will notice a device known as a torque converter. This device transmits power from the engine and gives it to the transmission. The torque converter also is responsible for the vehicle idling even though it is not in a gear.

Valve Body

A major component of the transmission is the valve body. It controls much of the transmission’s function. For instance, the valve body transmits hydraulic fluid to the valves to initiate the clutch pack to shift gears. The valve body is not just one piece; it consists of one-way check valves and solenoids.

Gear Set

In automatic vehicles, there is a gear set, commonly known as a planetary gear set, because there is a sun gear, three or more planet gears and a ring gear, much like the setup of the planets. The gears connect to a planet carrier, which keep them evenly spaced and assist the gears providing forward and reverse speeds.

Governor

The regulation of hydraulic pressure occurs because of the governor. This device uses centrifugal force in order to rotate it against the springs. Ultimately, this part signals when to shift, because of the oil pressure it pushes onto the shift valves.