How Automatic Transmissions Work

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!

How Clutches Work

You probably know that any car with a manual transmission has a clutch -- it connects and disconnects the engine and transmission. But did you know that automatics have clutches, too?

How CVTs Work

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.

How Differentials Work

Car wheels spin at different speeds, especially when turning. The differential is what lets a car make turns with ease. Find out how this key component allows the wheels to rotate at different speeds.

How Dual-clutch Transmissions Work

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.

How Gear Ratios Work

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.

How Manual Transmissions Work

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? Get the facts about your transmission.

How Sequential Gearboxes Work

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.

How Torque Converters Work

Cars with an automatic transmission have no clutch that disconnects the transmission from the engine. Instead, they use an amazing device called a torque converter. Find out all about the torque converter.

Why do some dump trucks have extra moveable axles?

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?

Why does my manual transmission car make a loud whirring noise in reverse?

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.