The throwout bearing, or clutch release bearing, is a key component in the automotive driveline. It is installed between the clutch and the transmission, and the specific seat is loosely fitted on the tubular extension of the bearing cover of the first shaft of the transmission. The main function of the release bearing is to push the pressure plate to separate from the friction plate to cut off the power output from the crankshaft by eliminating the heat and resistance generated by the direct friction between the clutch pressure plate and the fork when the clutch is pressed.

Working Principle of clutch throwout bearing

When the driver depresses the clutch pedal, the release bearing pushes the release lever forward, causing the clutch pressure plate to separate from the flywheel, thus cutting off power transmission from the engine.

When the driver releases the clutch pedal, the return spring pulls the release bearing back to its original position, causing the clutch pressure plate to re-engage with the flywheel and resume power transmission.

What are the symptoms of a bad throwout bearing?

A bad clutch throwout bearing（clutch release bearing）, will usually exhibit the following symptoms:

1. Abnormal noise:

   - A constant buzzing, hissing, or other metallic rubbing sound may be heard when the clutch pedal is depressed.

   - A sharp knocking or popping sound may be heard at the moment the clutch is disengaged or engaged.

2. Abnormal clutch operation:

   - The clutch pedal feels heavier and requires more force than usual to push it to the floor.

   - Clutch separation is not complete, resulting in difficulty in shifting gears or the vehicle shudders when shifting gears.

   - The clutch does not engage smoothly, the vehicle may not start smoothly or the clutch may engage suddenly while driving.

3. Power transmission problems:

   - It feels like the vehicle accelerates weakly and the speed increase is not obvious even if the engine speed increases.

   - The vehicle may not be able to maintain a stable speed in certain gears and slipping may occur.

4. Elevated Clutch System Temperature:

   - The clutch area may overheat, emitting unusual heat or odor.

5. Difficulty shifting gears:

   - Resistance may be encountered when attempting to shift gears, causing the shift lever to be difficult to move or stuck.

6. Clutch pedal vibration:

   - The pedal may vibrate abnormally when the clutch pedal is depressed or released.

7. persistent slipping gears:

   - The clutch does not fully lock, resulting in a mismatch between engine speed and vehicle speed, and the vehicle may slip out of gear unexpectedly while driving.

8. Change in clutch pedal travel:

   - An increase in free travel of the pedal may be felt when the clutch pedal is depressed, i.e., the pedal can move more distance before it begins to disengage the clutch.

9. Burning odor can be smelled:

   - Due to increased friction, a burning odor may develop in the clutch area, especially after prolonged driving or frequent clutch use.

10. Clutch system leaks:

    - If the clutch throwout bearing is damaged resulting in a poor seal, a hydraulic system leak may occur, as indicated by a reduction in clutch fluid or oil stains on the floor.

All of these symptoms indicate that the clutch throwout bearing may be damaged or worn and needs to be inspected and repaired promptly. Ignoring these problems may result in total clutch system failure, increasing repair costs and possibly compromising driving safety.

Please note that the above symptoms may vary depending on the vehicle model and the extent of damage. If damage to the clutch release bearing is suspected, it is recommended that the vehicle be taken to a professional automotive repair store for timely inspection and repair to ensure driving safety and vehicle performance.

Overhaul and Replacement of clutch throwout bearing

When overhauling the release bearing, a visual inspection will first be carried out to observe the wear of the bearing. If you feel a blockage or a noticeable sense of clearance when holding the inner race of the bearing by hand and turning the outer race, the bearing may need to be replaced.

If it is determined that the release bearing needs to be replaced, the appropriate steps will be followed for disassembly and installation. When installing a new bearing, make sure the housing and bearing surfaces are clean and free of contaminants, and apply the proper amount of grease.

In summary, the clutch throwout bearing plays an important role in the automobile transmission system, and its normal operation is of great significance to ensure the safety and stability of automobile traveling. Therefore, in daily use should pay attention to the clutch throwout bearing maintenance and maintenance, timely detection and treatment of potential problems.