A little Clutch Info.

[JaK FRoSTWhiTE]

Why Do We Need Clutches?

In a car, you need a clutch because the engine spins all the time and the car wheels don't. In order for a car to stop without killing the engine, the wheels need to be disconnected from the engine somehow. The clutch allows us to smoothly engage a spinning engine to a non-spinning transmission by controlling the slippage between them. To understand how a clutch works, it helps to know a little bit about friction.

Automobile Clutch

In the figure below, you can see that the flywheel is connected to the engine, and the clutch plate is connected to the transmission.

1pic. -Lets put the clutch in place!

2pic.Clutch plate =
3pic.Pressure plate =
4pic.Studs =
5pic.Diaphram Spring =
6pic.Throwout bearing = the throw out bearing is what actually pushes against the pressure plate to release the clutch disc.
7pic.Clutch housing = Houses the clutch
8pic.Release Fork =
9pic.Bell housing =

10pic.Lastly, the transmission.

How a clutch engages and releases ?

11pic When the clutch pedal is pressed, a cable or hydraulic piston pushes on the release fork, which presses the throw-out bearing against the middle of the diaphragm spring. As the middle of the diaphragm spring is pushed in, a series of pins near the outside of the spring causes the spring to pull the pressure plate away from the clutch disc (see below). This releases the clutch from the spinning engine.

What Can Go Wrong?

The most common problem with clutches is that the friction material on the disc wears out. The friction material on a clutch disc is very similar to the friction material on the pads of a disc brake, or the shoes of a drum brake -- after a while, it wears away. When most or all of the friction material is gone, the clutch will start to slip, and eventually it won't transmit any power from the engine to the wheels.

The clutch only wears while the clutch disc and the flywheel are spinning at different speeds. When they are locked together, the friction material is held tightly against the flywheel, and they spin in sync. It is only when the clutch disc is slipping against the flywheel that wearing occurs. So if you are the type of driver who slips the clutch a lot, you will wear out your clutch a lot faster.

Another problem with clutches is a worn throwout bearing. This problem is
heard by a rumbling noise whenever the clutch engages

[Raceboy]

wow good right up jack very informative!....now can you do one on why i need an automatic?????

[wed3k]

so burnouts do NOT take out the clutch disc

[trendyexr]

Depends on how you let off the clutch.. if you ease it off, that is hard on the clutch (for burnouts).

[wed3k]

Depends on how you let off the clutch.. if you ease it off, that is hard on the clutch (for burnouts).

naw man, you let it out to the point right when it is about the slip and then pop it...

[trendyexr]

naw man, you let it out to the point right when it is about the slip and then pop it...

Lol, thats why I said it depends on how you do it...

[green5thgen]

Nice write up. Once thing I would add though is that burnouts are bad and this is why. Like it was said, the flywheel and clutch turning at different speeds causes the friction material to wear away. But also when you rev the motor and dump the clutch the severe heat from the friction it takes to lock the flywheel and the disc together causes hot spots on the flywheel and pressure plate thus making it harder and harder over time to get a good surface for them to grip. This will cause premature wear as well. Just a thought you might want to add.
Great writeup.