The clutch in your car is the disc which disengages the power flow from the engine in order to allow you to change gears. There are three main parts of the clutch: the pressure plate, the driven plate, and release bearing.
Types of Clutch Failure:
If your clutch is slipping it means that power is not being delivered to the wheels when the clutch engages, therefore the car will not move. There are several reasons for the clutch to slip, these are as follows:
• Worn Pressure Plate
The pressure plate is attached to the flywheel, therefore it is also exposed to heat which can cause warping and friction can cause it to wear down which will, in turn, affect the pressure. This will also cause the clutch slip and judder.
• Worn Release Bearing
The release bearing operates the pressure plate and is constantly spinning, which means it may become worn out, thus losing its lubrication. You’ll be able to tell that the release bearing is worn out if you hear a squeaking sound whilst the car is running, or when you depress the clutch it isn’t as smooth as it should be.
Bearing failure can be a result of the clutch slipping due to high pressure, the superfluous heat generated by this will either melt or destroy the bearing seal, and may destroy the clutch. You can also tell if the clutch is slipping if the car hesitates before accelerating or if the RPMs are too high.
Sticking / Not Clearing
Not only can there be problems with the clutch slipping, but also with sticking, when the clutch will not release properly. The reasons for this are as follows:
• Warped Flywheel
The flywheel is attached to the end of the crankshaft and due to friction, may overheat over time which can cause warping. You’ll be able to tell that the flywheel is warped if you hear what is known as “clutch judder,” these are vibrations when you let go of the clutch. It will not be smooth when you pull away, hence the term “judder.”
• Air in the hydraulic line line
This takes up the space the fluid needs to build pressure. Clutch fluid will not compress in a clutch line but air will, so if there is air in the system the full pressure will not be applied to the clutch.
• Leaking Master/Slave Cylinder
Hydraulic clutches require fluid from cylinders to activate the clutch, however, if the cylinders lose fluid they won’t be able to produce the hydraulic pressure needed. This is usually indicated by an unusual smell or liquid pooling underneath the vehicle and would be due to worn seals on the clutch master/clutch slave cylinder or a split clutch pipe.
• Stretched or broken clutch cable
The clutch cable needs the correct tension to operate properly. Aside from sticking, another way to tell if this is happening is if the clutch pedal sinks to the floor without any pressure felt on the peddle, or the transmission slips out of gear.
The diaphragm in the clutch cover could be worn, causing the pressure to be reduced for the clutch not to work correctly.
The main signs of clutch failure to look out for are:
• Squeaking noise when the clutch is pressed
• Poor acceleration
• A sticking or loose clutch pedal
• Problems changing gear
If you feel that there is a problem with your clutch, bring your car in to get checked out today!
Written by Amber Callender