Q: How Does a Clutch Work?

asked by on December 01, 2015

How does a clutch work in a manual transmission?

A clutch for a manual transmission is not a single part, but many parts put together to form the clutch assembly that is part of the clutch system. The parts in a clutch assembly are the clutch pressure plate, clutch disc, clutch release bearing, flywheel, clutch release fork and pilot bearing. The clutch system consists of the clutch assembly, clutch cable, clutch pedal, and bracket. Some clutch systems use hydraulics to move the clutch instead of the clutch cable. The system has a clutch master cylinder, fluid pressure line, clutch slave cylinder, and a different release fork or no fork at all, mounted on the front of the transmission.

The clutch pressure plate is bolted to the flywheel with the clutch disc sandwiched between them. The pressure plate keeps high pressure on the clutch disc causing it to press against the flywheel. The clutch disc has material mounted to it with rivets or glue similar to brake pad material. The disc has center splines that slide on and lock to the transmission input shaft. The input shaft is supported on its tip by a pilot bearing or bushing in the center of the flywheel or rear of crankshaft. The clutch release bearing slides on the front of the transmission and is pressed on the pressure plate fingers to release its pressure on the clutch disc. This allows the engine and transmission to spin free of each other.

The clutch operation starts with the operator pressing in the clutch pedal. The pedal arm will pull in on the cable or the arm will push in on the rod to the clutch master cylinder. The cable will pull on the clutch release fork or the clutch hydraulic slave cylinder will press in the clutch fork. The fork or slave cylinder pushes in the release bearing to press on the clutch pressure plate to release the clutch. As the pressure plate is pressed, it takes off pressure on the clutch disc and allows the transmission to be shifted. Once a gear is selected, the clutch pedal is released and the pressure plate then applies pressure on the clutch disc. As pressure is applied, the clutch disc is locked to the pressure plate and flywheel to turn the transmission input shaft.

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

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Calipers keep locking up even after replacing.

You need to have the brake master cylinder checked to see if the brake booster actuator pin is not adjusted correct and causing the brake master cylinder to hold partial pressure to the calipers. The caliper slides should also be...

Slow slipping transmission, how much longer will it last?

If you are out of warranty, you'll need to have your vehicle checked for problems with a qualified technician such as YourMechanic. They can come to your home or office, perform a road test, check your transmission for mechanical or...

strange problem

Hello. The symptoms you are experiencing can be caused by a wide variety of issues. If the symptoms appear to come and go then it may be possible that the symptoms are electrical in nature. A few things I would...

Related articles

How a Cable Clutch System Works
If If you drive a car with a manual transmission, you know that to get your car moving, you depress the clutch pedal, choose a gear, and then give the vehicle a bit of gas. But have you ever wondered...
The 10 Transmission Problems to Never Ignore
There’s nothing quite like transmission problems to stress out the average car owner. They are, at best, inconvenient and, at worst, very expensive. Proper...
How Long Does Clutch Fluid Last?
The The usual answer to this is, forever. Of course, as is the case with many hard and fast answers, there are always exceptions. The reason that your car clutch fluid should last forever is that it’s a closed system....