Types of Automatic Gearboxes

Automatic transmissions come in many different types.Modern leather interior of the new car image by terex from Fotolia.com

Automatic gearboxes are integral elements of any automatic transmission system. Automatic transmissions have become more and more common due to their ease of use. Several major types of automatic gearboxes are in wide use today, all of which achieve the same goal---switching gears automatically---but do it in different ways. If you are interested in transmissions and the way they work, this is an excellent place to start.

Torque Converters

Torque converter automatic gearboxes are the oldest type of automatic gearbox. They are very easy to use and allow for a smooth ride but are also not very fuel efficient. However, they are extremely reliable. Torque converter automatic gearboxes can be designed to have any amount of gears, and the more gears that are built into one, the more efficient the gearbox. These gearboxes are powered by the turning of a shaft, which connects the engine to the transporter.

Continuously variable transmission (CVT) automatic gearboxes are used only by a few auto manufacturers, including Honda, Nissan, Audi and Mercedes. In addition, CVTs are also usually used only in smaller vehicles. They tend to be more reliable and fuel efficient than torque converter automatic gearboxes. They always come with seven speeds.

Direct shift automatic transmissions were created by the Volkswagen Audi Group, and they appear in cars made by this manufacturer, such as Volkswagen, Audi, Skoda and Seat. They come with six speeds, and they are known for their fast shifting ability as well as their fuel efficiency.

Automated manual transmission, or AMT, gearboxes consist of a strange hybrid of manual and automatic transmission types. They essentially consist of a manual-style gearbox that is nevertheless operated automatically by the vehicle's onboard computer. Often, you can choose between either a fully automatic mode or a manual mode. Since a computer switches the gears, AMTs have much lower levels of gear wear as well as increased fuel economy.

Types of automatic gearboxes can also be differentiated by their location in the vehicle. Front-wheel drive automatic transmission gearboxes are positioned in the front of the car and tend to be smaller and more compact. They are mounted in the engine compartment and are sometimes referred to as "transaxle." Rear-wheel drive automatic gearboxes are situated near the back wheels and tend to take up more space.