Do you hear a grinding sound whenever you step on the clutch to shift gears? If your answer is yes, then your clutch release bearing is probably worn out. Have your mechanic check it right away and don't wait for your clutch assembly to become a grinding machine. Get a replacement as soon as you can.
The release bearing or the throwout bearing is located around the transmission input shaft at the back of the pressure plate. It decreases the friction between the release fork and the clutch pressure plate levers, preventing them from wearing out. To do this efficiently, the bearing should be finely lubricated. There are many types of release bearings, like mechanical bearings and hydraulic bearings. The former depends on proper lubrication, while the latter works with an external clutch slave cylinder. It should be noted that hydraulic bearings are more prone to leaks compared to mechanical bearings.
When you shop for release bearing replacements, you should know which type you need or prefer. Different types are suited for different applications. Also, for superior performance, make sure the replacement is a direct-fit to your car model. Lastly, make sure that the prospective replacement is designed to meet or exceed OEM standards.