How a Clutch Engages and Disengages

In your car transmission, the clutch is a device that works to engage and disengage the moving parts of your drive shaft. For purposes of this discussion, we’ll focus on manual transmissions.

The moving parts are the transmission input shaft and the engine crankshaft. The engine rotates at different speeds, and the automobile transmission’s gears need to be shifted. When you’re shifting your car, the power of the engine is delivered to the wheels. That, in a nutshell, is how your transmission works.

The clutch

The clutch assembly contains a number of small parts, but the main components are:

  • Flywheel: This is connected to the crankshaft and spins with the motion of the engine.

  • Pressure plate: This is bolted to the flywheel. It’s spring-loaded, so it holds the assembly together and also releases the tension that allows it to rotate freely.

  • Disc: The clutch disc is located between the pressure plate and the flywheel. It has friction surfaces, something like a brake pad, that makes and break contact with the flywheel and the pressure plate.

  • Throw-out bearing and release system: The throw-out bearing and the release system work together to engage and release the clutch.

The transmission’s input shaft runs through the middle of the pressure plate, flywheel and clutch disc, taking the engine’s power and sending it to the wheels by way of the gears. Where the shaft enters the transmission, there is a bearing that takes most of the shaft’s load. In the center of the flywheel is a smaller bearing that centers the shaft so it can rotate as the clutch assembly engages and disengages. This is what the clutch disc is connected to.

The clutch pedal

When your foot is off the clutch pedal, everything spins together. When you press the pedal in, the assembly disengages. As you let the pedal out, the friction surfaces on the disc comes into contact with the pressure plate and flywheel, and you’re moving. The idea is to match the engine speed to the point where the friction surfaces engage so that you don’t end up stalling the engine.

Now you know how your clutch works. Do you know how to drive a manual transmission? Maybe it’s second nature to you. If it’s not, why not learn? Just make sure you don’t ride the clutch and end up stalling!


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How to Shift From First to Second Gear in a Manual Transmission Car
Shifting from first to second gear in a manual transmission requires accuracy and practice, as well as a feel for the car.
What Do the Press Clutch or Press Brake Pedal Warning Lights Mean?
The press clutch and press brake pedal lights remind you to press on the brake or clutch before starting the engine or while in park mode.
How to Troubleshoot a Clutch Pedal Sticking to the Floor
Clutch pedals in manual cars stay on the floor if there's a failed clutch release bearing, slave cylinder, clutch master cylinder, or clutch linkage.

Related questions

Clutch noise
Without being able to hear the noise it will be hard to suggest a cause and repair. A common issue is the dust cover on the transmission. The noise will sound like a rattling and then go away once the...
stiff gear change
Hey there. One of the problems associated with buying a used car is having accurate data on how the previous owner maintained the vehicle. When you mentioned that after diagnostics were completed, that the technician discovered that dirty oil was...
Fluid hose comes off transmission to the slave cylinder.
The clutch master cylinder is not relieving the pressure when applied. I recommend bleeding the clutch master cylinder and retest. If the condition continues, then replace the clutch master cylinder (https://www.yourmechanic.com/services/clutch-master-cylinder-replacement). If you need further assistance with your hose blowing...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com