When driving a vehicle with a manual transmission, the first thing you need to do to shift up or down is to press the clutch pedal. But what happens when you engage it? When you press the clutch pedal, you cause a special mechanical device located between the engine and the transmission to disconnect them from each other. This device is called a clutch. It is an essential part of any vehicle equipped with a manual transmission, allowing for smooth and safe gear shifting in motion. If it fails to operate properly, you will not be able to go into gear.
A typical clutch features three main components, including a pressure plate, a clutch disk, and a release bearing. Let’s describe them in detail.
A clutch disk is used to connect the transmission to the engine. It sits on the transmission input shaft and is coupled with the flywheel attached to the crankshaft when the clutch pedal is released. Thanks to the friction material it is covered with, the clutch disc ensures a super reliable joint, causing the input shaft to spin together with the flywheel.
A pressure plate does exactly what its name suggests. Attached to the engine, it applies pressure to the clutch disk using coil springs or a diaphragm. This holds the clutch disk against the flywheel, preventing slipping.
This is a sealed or roller bearing that rests on the input shaft bearing retainer, and puts force on the pressure plate when you press the clutch pedal, causing it to disengage the clutch disk.
Depending on a vehicle, the clutch operation can be achieved using one of the following clutch release systems, including mechanical, cable and hydraulic. While the latter one is the most common type of clutch release system found in modern vehicles, all of them do the same job, converting a step on the clutch pedal into the motion of the release bearing.
What happens if I drive a vehicle with a bad clutch?
Hard shifting and engine stalling are just to name a few of the problems that can be caused by a faulty clutch. Here are the most common problems you may face:
If your engine’s speed increases, but your vehicle’s speed does not, you may have a slipping clutch. This usually happens due to a stuck clutch pedal.
Grabbing or jerking when driving
This is an indicator of a worn-out flywheel or clutch disk. They should be inspected for physical damage.
You may notice a growling or chirping noise when the clutch pedal is depressed or a grinding noise when shifting. The first one is a sign of a bad release bearing, while the other one says about a worn-out pressure plate or clutch disk.
It’s hard to change a gear
If you have pushed down the clutch pedal, but it’s hard to shift up or down, most likely, your clutch is worn-out or damaged. This problem should be addressed quickly to avoid damage to the transmission.
Poor clutch pedal
If your clutch pedal feels “weak”, you should check the hydraulic system for leaks. In some cases, you may need to adjust the clutch.
You can’t shift a gear
Your clutch must be disengaged, so you can go into gear. If this doesn’t happen, you might have a bad pressure plate or release bearing,
Your engine stalls
If your engine stalls, while you’re trying to change a gear, your clutch might not be disengaged due to a worn-out release bearing or pressure plate.
How to fix a bad clutch
Repairing a clutch involves a lot of expensive labor, so it must be properly diagnosed by a professional before any replacement or repair is done. When the problem is detected, your mechanic will need to disassemble the transmission and remove several other parts under the hood to access the clutch. Once it is replaced or repaired, the mechanic will reinstall all removed components and the transmission as well as provide some kind of adjustment to make the clutch perform properly.
If there are any marks of engine oil or transmission fluid inside the clutch, the source of leaks must be detected and fixed before reinstalling the clutch and the transmission. Your mechanic can recommend you to replace the clutch’s rear main seal and some other seals to prevent costly repairs in the future.
The service life of your clutch also depends on your driving habits. For example, if you got used to resting your foot on the clutch pedal, this may lead to its premature failure.