The clutch release bearing, or throwout bearing, enables the clutch release mechanism to operate. When the drive presses on the clutch petal, the clutch linkage moves the bearing/ Then the bearing pushes or pulls the release levers inward or outwards to disengage the clutch.
The clutch release bearings often fail due to wear over time, binding, or they are out of lubricant. When any of these happens, the clutch will become noisy while engaged and the clutch bearings will need replacing.
Most manufacturer factory warranties and extended warranties do not cover the clutch release bearings. However, they still need to be maintained in order to ensure the validity of your manufacturer factory warranty and extended auto warranty, if applicable.