Car Transmission and Drivetrain Systems

Upkeep of your transmission may save you money in the long run. Learn manual and automatic transmission basics, then move on to clutches, differentials and torque converters.

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Car wheels spin at different speeds, especially when they're turning. So how does the differential help make them turn with such ease?

By Karim Nice & Talon Homer

Sales of stick shifts are down around the world and even some sports car manufacturers have stopped making them. Still, many zealous auto enthusiasts are doing all they can to keep the old three-pedal motion alive.

By Talon Homer


You've proudly driven a stick shift all your life, so you already know that manual transmissions accelerate faster than automatics. End of story. Well, that was once true, but things have changed.

By Cherise Threewitt

Manual transmission synchronizers are devices that eliminate the need for double clutching when changing gears. Learn how manual transmission synchronizers work in this article.

By Contributors

You find liquid leaking from your car and are at a loss about what to do. Learn about how to identify a transmission fluid leak in this article.

By Contributors

Manual, automatic, sequential, dual-clutch -- these are just a sample of what you'll see in this image gallery. Check out pictures of all types of transmissions right here.


Anyone with a manual transmission knows that a clutch connects and disconnects the engine and transmission. But did you know that automatics have clutches, too? Read on to discover how a clutch car works!

By Karim Nice, Charles W. Bryant & Kristen Hall-Geisler

Most people know that cars come with two basic transmission types: manuals and automatics. But there's also something in between that offers the best of both worlds -- the dual-clutch transmission. Check it out.

By William Harris

Traction control helps limit tire slip in acceleration on slippery surfaces. Many of today's vehicles employ electronic controls to limit power delivery for the driver, eliminating wheel slip and helping the driver accelerate under control.

By the Editors of Publications International, Ltd.

In a regular transmission the gears are literal gears -- interlocking toothed wheels. Continuously variable transmissions, on the other hand, don't have interlocking gears. The most common type operates on a pulley system. Learn all about the smooth-operating ultra-efficient CVT.

By William Harris


Combine the ease of an automatic with the driver control of a manual and what you've got is a sequential manual transmission. A simple forward push advances the gear. Learn all about the sequential gearbox.

By Marshall Brain

Both automatic and manual transmissions accomplish exactly the same thing, but they do it in totally different ways. And it turns out that the way an automatic transmission does it is pretty amazing!

By Karim Nice

Manual transmissions use mostly helical gears, but reverse is a special situation that requires a different type of gear -- a spur gear. Learn why a spur gear makes a loud whirring noise when the car's in reverse.

I see many dump trucks with wheels on two rear axles on the ground and a third axle with elevated wheels that can be lowered. These seem to be used when the truck is full -- but why include what must be expensive hardware to raise and lower the wheels? Why not just keep them down at all times?


What does that funny "H" pattern on my car's gear shift have to do with my transmission? How does it make the car change gears? And when I mess up and hear that horrible grinding sound, what is actually grinding?

By Marshall Brain, Cherise Threewitt & Sascha Bos

Gear ratios are what allow a car to reach a high rate of speed or climb a steep hill. Learn about gear ratios, gear trains and planetary gear systems.

By Marshall Brain