What happens when the clutch is loose at the start?

On the issue of abnormal noise of automobiles, it is difficult for ordinary car owners to distinguish which ones are abnormal noises and which ones are reasonable abnormal noises. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. In the case of a turbocharged engine, there is a must be a difference between the sound and the sound of a naturally aspirated engine; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that because of their own lack of understanding of mechanical knowledge, they should be cautious about the sound of the car to avoid wasting time and energy.

Second, the identification method of car noise:

In practice, due to the limitations of working conditions, it is difficult to measure the sound of the car with special instruments, and the sound of the car can only be described and compared with the judgment of the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound similar to the small hammer hitting the cement floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary wide disassembly, first of all, it is necessary to distinguish between normal sound and abnormal sound. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noises of automobiles, attention should be paid to creating good auscultation conditions and trying to eliminate the interference of other noises, so as not to affect the accuracy of judgment.

It is best to consciously amplify or reduce the sound, that is, use a screw or other metal rod as a stestological instrument to contact the sound part to amplify the sound, or use a single cylinder fire cut-off to reduce the sound to meet the diagnostic needs. The auscultation site should be kept quiet to minimize human interference.

The vehicle starts and makes a sound just when the clutch pedal is relaxed.

1. When the clutch is about to be combined, you hear a sharp whistling, step on the pedal, the sound disappears, and the relaxation pedal appears again, which is caused by the broken steel plate of the driven disc or the exposed scratching pressure plate or flywheel of the rivet head, which should be overhauled.

2. At the moment of combination or separation, if the clutch emits a "click" and "resistant" metal impact sound, and it is more obvious when the heavy vehicle starts, it is the spline hole of the driven disc and its shaft to match the plate, and when it is serious, it should be overhauled or replaced; If you hear a "click" sound, it is the sound of the driven friction plate loosening on the steel sheet or the impact between the separation lever and the window hole.

3. The clutch pedal is lifted at a very slow speed, and the vehicle crashes into the start, making a "pop" sound. This is caused by the sudden engagement of the main and driven parts, and the reasons come from two aspects: first, the rod train transmission is stuck, so that the pressure plate is suddenly pressed to the driven plate, causing the car to break in; The second is that the driven disc is deformed or the friction lining is stained with oil, which causes the clutch to continue to engage and cause collision.

The answer is that the clutch release bearing is poorly lubricated, loose wear or abnormal noise caused by damage, and it is necessary to add lubricating oil to the clutch release bearing or replace it in time. When lifting the clutch pedal, it is necessary to follow the operating principle of one fast, two slow, and three linkages. When starting, press the clutch pedal to move neatly, one foot to the end, so that the clutch is completely disengaged.

Three, when the clutch pedal is stepped on to 3 4, the clutch should be firmly engaged, otherwise check whether its stroke is appropriate, you can use a ruler to measure at the pedal, first measure the height of the highest position of the pedal, and then measure the height when you step on the pedal to feel resistance, the difference between the two values is the value of the clutch stroke of the car.

Hello, if you have no other questions about this problem, you can click on the upper right corner of "End Service" and give a like. Click on the avatar to follow me, and if you have car-related questions in the future, you can ask me again.

I hope I can give me a thumbs up, it's very important to me, good people have a safe life.

There are two cases of cleft squeak when the clutch is pressed:

The owner's operation method is wrong, and it will make a sound if you don't step on it properly.

The clutch pressure plate spring is broken or the separation bearing is loose, and the clutch steel plate is broken; The clutch release lever is broken, worn excessively, or the release lever adjustment bolt is broken. Most of the clutch release bearings have quality problems.

The clutch is located in the flywheel housing between the engine and the gearbox, and the clutch assembly is fixed to the rear plane of the flywheel with screws, and the output shaft of the clutch is the input shaft of the gearbox.

While the car is moving, the driver can press or release the clutch pedal as needed to temporarily separate and gradually engage the engine from the gearbox to cut off or transmit the power input from the engine to the transmission.

The clutch is a common component in mechanical transmissions, allowing the transmission system to be disengaged or engaged at any time. The basic requirements are: smooth jointing, rapid and thorough separation; Easy to adjust and repair; Small overall dimensions; Small mass; Good wear resistance and sufficient heat dissipation capacity; The operation is convenient and labor-saving, and the commonly used ones are divided into two categories: tooth inlay type and friction type.

Please click Enter a description.

Please click Enter a description.

Fault analysis and troubleshooting: Grasping the timing of abnormal noise is an effective way to diagnose clutch faults. Identification is carried out by stepping on the clutch pedal. When stepping down or relaxing the pedal, there is a "rustling" sound, and you should check whether there is a free stroke.

If the abnormal noise disappears after adjusting the free stroke, the working condition of the release bearing can be further checked. If it is not serious, it can be continued to be used and replaced during maintenance. When the pedal is lightly pressed (eliminating free stroke), there is a "rustling" sound, which is usually a damage to the release bearing.

This is because the inner end of the diaphragm spring is in contact with the release bearing. If the disengaging bearing is in good condition, it should not be stepped down on the basis of the light pedal, if there is a similar collision, impact of the abnormal sound, usually caused by the clutch cover bolt loosening. When the pedal is pressed to the bottom, there is an abnormal sound of "bang, bang", which means that the driven disc is damaged or the spline is worn.

When the car starts and the clutch is semi-disengaged, there is an abnormal sound, indicating that the driven disc shock absorbing spring is damaged or the driven disc hub rivet is loose.

1. Reason:

1. The separator bearing lacks lubricant, resulting in dry grinding or bearing damage.

2. There is no gap between the release bearing and the inner end of the release lever.

3. The oil stain and dust between the separation bearing sleeve and the conduit are serious or the separation bearing return spring and pedal return spring are fatigued, broken and falling off, so that the separation bearing return is not good.

4. The spline hole of the driven disc is loose with its spline shaft.

5. Annealing, fatigue or breaking of the driven disc damping spring.

6. The rivet of the friction plate of the driven disc is loose or the rivet head is exposed.

7. The pin holes of the double-plate clutch transmission pin, the intermediate pressure plate and the pressure plate are worn loosely.

2. Diagnosis and exclusion:

1. Press the clutch pedal slightly, so that the release bearing is in contact with the release lever, if there is a "rustling" sound, it is the release bearing; If it still rings after refueling, it means that the bearing is excessively worn, loose or damaged and should be replaced.

2. Step on and lift the clutch pedal, if there is an intermittent collision sound, it means that there is a series movement before and after the separation bearing, and the return spring of the separation bearing should be replaced.

3. Even when stepping on the pedal, if there is a sound when the clutch is just engaged or separated, it means that the rivet of the driven disc is loose or exposed, and the driven disc should be replaced.

Precautions for clutch use.

First, the clutch is trembling.

At the start, the clutch does not engage smoothly and produces jitter. It may be that the separation bearing is severely worn or lacks oil; The friction plate is oily or too smooth; The elastic force of the diaphragm spring decreases, causing the detractor to shake; Engine mount bumpers that are too soft or damaged, etc. The owner can disassemble the clutch assembly, carefully check the friction plate, damping spring, spline, etc. of the driven disk, and must replace it if it needs to be replaced.

Second, the clutch slips.

The cause of slippage may be the loosening of the connecting bolts between the clutch cover and the flywheel, the wear and thinning of the friction plates, and the compression spring being too soft; Oily, greasy or stuck and unable to return to its position, etc.

The owner can start the engine, tighten the parking brake, hang up the low-speed gear, slowly relax the clutch pedal, and gradually press the accelerator pedal to start. If there is oil stain, it should be removed and cleaned with gasoline and dried.

Gently press the clutch pedal, when the clutch release bearing and the release lever are in contact, there is an obvious "rustling" sound, which can be judged to be the clutch release bearing. At this time, the release bearing can be greased, if it still sounds after adding grease, the release bearing is damaged. If the separating bearing has a stuck phenomenon or the axial clearance is too large, a new bearing should be replaced.

If the wear of the inner ring of the bearing is greater than.

Repair, maintain and select cars, one-stop interpretation of car knowledge.

Let's talk about buying a car, using a car, maintaining a car, and repairing a car.

If it is the pedal in the car, it may be caused by the lack of lubricating oil in the return spring of the clutch pedal, you can add lubricating oil to try it, if there is still a need to replace the clutch pedal assembly. If it is issued from outside the car, it is likely that the disengagement bearing in the clutch system is wearing fault. This requires the replacement of the clutch release bearing.

The specific fault needs to be checked before it can be determined.

There is an abnormal noise in the drive, the clutch three-piece set may be broken, and the gearbox is damaged. If you just loosen the clutch and there is an abnormal sound,