What is a clutch release bearing?

A clutch release bearing, also known as a clutch throwout bearing, is an important part of the clutch system. It is usually installed between the clutch pressure plate and the transmission, and its operation is controlled by the operation of the clutch pedal. When the driver depresses the clutch pedal, the clutch release bearing is pressurized and pushes the clutch pressure plate backward, thus separating the clutch disc from the flywheel and cutting off the power transmission between the engine and the transmission. On the contrary, when the driver releases the clutch pedal, the clutch release bearing releases the pressure, and the clutch pressure plate moves forward under the action of the spring, so that the clutch plate and the flywheel are closely combined to realize the transmission of power.

The performance of the clutch release bearing directly affects the smoothness of clutch operation and service life. Therefore, in the process of vehicle use, attention should be paid to the maintenance and repair of the clutch release bearing, timely detection and treatment of faults to ensure the normal operation of the vehicle.

Symptoms of clutch release bearing failure include the following:

1. Strange noise: when the engine is idling, press the clutch pedal lightly, and when the free stroke is just eliminated, you will hear the sound of “rustle” or “squeak”. Continue to step on the clutch pedal, if the sound disappears, it may not be a release bearing problem; if there is still a sound, it is likely to be a release bearing sound.

2. Starting difficulties: when the clutch pedal is depressed, the engine is difficult to start, the crankshaft feels heavy with the hand crank, release the clutch pedal into neutral in order to start the engine smoothly. This may be due to the separation bearing erosion, resulting in greater friction between it and the clutch release lever.

3. Engine stalling: When the engine is idling, as long as the clutch pedal is depressed, the engine will stall immediately. This may be because the release bearing is damaged and cannot work properly, resulting in incomplete clutch release.

4. Dry friction: Some drivers are used to using half-leg clutch, which puts the clutch in half-engagement and half-disengagement state, causing dry friction of the clutch, and the heat is transferred to the release bearing, resulting in thinning and loss of grease inside the bearing, and the bearing is damaged by abrasion when the temperature reaches a certain value.

5. Wear and poor lubrication: after a long time of use of the release bearing, especially in high temperature, the grease is dissolved and gradually thrown away in the bearing operation, the bearing has dry friction and heat, resulting in abrasion, hysteresis, and loss of separation function.

6. Dust erosion: separation bearing by dust erosion, grease deterioration, exacerbating its damage.

7. Poor fit: the separation bearing and the separation sleeve with poor, especially the two fit clearance is too large, loose, and not in a plane, the work of the separation bearing by the impact load, so that the track wear, ablation.

8. Pedal stroke problem: the clutch pedal free stroke is too small or not, so that it is in a state of frequent engagement, causing fatigue damage or even ablation; pedal stroke is too large, causing the clutch separation is not complete, difficult to gear, the clutch is in a state of half-engagement and half-disengagement, resulting in dry friction, the heat is transmitted to the release bearing, so that grease runs out, bearing ablation.

9. Difficulty in clutch operation: when the driver depresses or releases the clutch pedal, he will feel obvious resistance or stagnation, and even need to use force to operate.

10. Unsmooth shifting: Due to the problem of the clutch release bearing, the vehicle may experience stuttering, impact or noise when shifting gears, affecting the smoothness of driving.

11. Clutch slippage: In extreme cases, the failure of the clutch release bearing may result in the clutch plate not being able to make full contact with the flywheel, thus causing the clutch to slip and affecting the power output of the vehicle.

12. Other mechanical failures: Broken clutch pressure plate spring or loose release bearing, broken clutch steel plate; broken or excessively worn clutch release lever or broken release lever adjusting bolt.

If the clutch release bearing shows any of the above symptoms, it should be inspected and repaired in time to avoid further damage and safety hazards. Usually, once the release bearing fails, it needs to be replaced in time because the repair cost may be high and the disassembly and installation process is complicated, which will take a lot of man-hours.