When Should I Change the Clutch of My Car

The clutch is a device in your car which connects shafts and allows to to change the amount of power supplied to the engine. A common misconception is that automatic cars do not have clutches, but this is inaccurate. It is only the clutch pedal which is absent in most automatic cars. The clutch system still exists in the engine of the car, it just works differently.

Automatic cars generally have two type of clutch. One is an automatic torque converter (ATC). This is when the rotation of the wheel (torque) increases to the point that it will automatically engage the clutch and change gear. The other is a dual-clutch system which has a clutch apiece for even and odd numbered gears. Many use electrohydraulics to make it one of the smoothest kinds of clutch system you can get. Many also have paddles on the side of the steering wheel which allow you to change the gear in semi-automatic cars.

In a manual car, what many refer to as a clutch is simply the clutch pedal, not actually the clutch itself. It is like calling a light switch 'the light' when all it is is a way of operating the light. Manual cars require the driver to engage the clutch themselves by depressing the pedal. The driver will know when to change by keeping an eye on both the revs and speed of the car. Clutches often wear out through misuse, so drivers need to be careful to make gear changes as smooth as possible.

A dry clutch is a type of clutch which uses friction to change gears and is the most common. When a disc from a dry clutch wears thin you will notice scratching when selecting a gear. If this happens it means that the disc failed to properly fulfil its function of transmitting the power from the gearbox to the drive wheels. Many clutches also have dampers to try to stop the vibrations of the car from damaging the clutch when changing. If there is a rattle, it might be the dampers rather than the clutch wheel itself which are at fault, but it will still have a negative effect on the clutch.

Wet clutches are those which are bathed in lubricant to make transitions smoother. Because of this, they tend to last longer than dry clutches. However, they are thought by some to lose power to the liquid. You can tell a wet clutch is faulty by the quality of the lubricant. If there are pieces of something in it, it is likely due to a faulty clutch. Similarly, if the liquid smells burnt it is a sign the clutch is wearing too strong.

A clear sign that theclutch has to be changed is when we find that, when trying to overtake or when going up hill, we accelerate and the motor increases revolutions but speed doesn't go up as it should. Similarly, if the clutch is worn, the revs won't settle as quickly as they should, especially in higher gears.

If you have a hydraulic clutch, you may have to make sure there is no air in the hydraulic system. If there is air in the system, it can be leading to problems when shifting gear. Flush out the system or, if you don't feel comfortable, ask your mechanic to do so for you.

One of the most obvious signs it is time to change your clutch, happens when you are changing between gears. If the clutch slips, you will notice a lack of smoothness when shifting from one gear to another. You may even hear a scratching noise or difficulty in selecting gears even though you are at an appropriate level of revs for a gear change.

Diagnosing a slipping clutch is obvious in some cases, but much harder to determine in others. Sometimes it is accompanied by noise, but often it is the feel of the clutch pedal (in stick shift manual cars) which can show you it is time to get your clutch fixed or replaced. These include:

• higher revs of the engine without increase in speed
• a loose pedal which seems to be depressed when in gear
• if the accelerator pedal doesn't seem to work as well as it has done previously

When you release the clutch, there should be about 1" of movement in the pedal before the clutch disengages. If this isn't the case or if you feel particular sensitivity in the clutch pedal, it has likely been overworked. If you are driving on the open road or the highway, you may not notice the clutch as much. It will be more evident when driving in areas where you have to change the gear a lot.

From the physical point of view, the unusually short route of the the clutch pedal is signalling that the disc is starting to wear out.

We can do a test to check the degree of clutch wear. It is relatively simple, however, it should not be done frequently as the check itself contributes to shortening the life of the component. We must have the motor of the car switched on and the hand brake engaged. Do not do this near anywhere the car can do damage if it lunges forward. It should not lunge, but it is better to be safe than sorry.

Once you have the engine on and the gear in third, slowly lift your foot off the clutch and depress the accelerator. This is known as getting the bite point, just as you would when starting off in first gear. As the car is in third gear, the car should stall. However, if the car takes a little while to stall, it is likely you have a worn out clutch. The longer it takes the car to stall the more worn out the clutch is.

As mentioned, there is no established mileage or time frame in which to change the clutch. This is because it depends on a list of different variables. These can include:

• Quality of the driver: stick shift manual cars are not as easily driven as automatics. If the gears are changed sloppily and/or at the wrong level of revs, it will wear out the clutch more quickly.
• Loads being carried: if your car is used to pull trailers, caravans or horse boxes, you will likely put more wear on the clutch as the weight pulls on the engine.
• The clutch fluid is low: make sure you check your clutch fluid to see if it is at the right level and quality.
• Age of the car: like most car parts, the older it is the less likely it will hold out for very long.
• Area car is driven: in hotter climates, the clutch fluid will heat up, thin out and become less efficient.

In general, a car clutch should last anywhere between 30,000 and 100,000 miles. However, depending on the above variables, clutches can last more or less mileage. If you are worried about the clutch and have noticed any of these signs you need to change your clutch, then take it to a mechanic for a second opinion.

Changing the clutch is not an easy task, so either go to a professional or get help from someone who knows what they are doing. It might be a little costly, but a bum clutch can result in engine failure which increases chances of an accident, especially at high speeds. It is always better to be safe than sorry when you see car parts wearing thin.

If you want to read similar articles to When Should I Change the Clutch of My Car, we recommend you visit our Car Maintenance and Repair category.