The reason why the chassis sometimes creaks and creaks

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 they lack their own understanding of mechanical knowledge, so they can distinguish the abnormal noise of the car and 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 disassembly, we must first distinguish between normal sound and abnormal noise. 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 noise, 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.

Check that the connections between the chassis components are tight. When the chassis bolts and screws are loose, the bolts and nuts should be tightened or replaced in time.

Check the drive shaft and universal joint for deformation or oil leakage. If the transmission shaft and universal joint are deformed, they need to be replaced in time. If it's just a lack of oil, it needs to be relubricated.

If necessary, the oil seal should be replaced. Check whether the brake calipers and brake disc brackets are loose, and check whether the brake pads are loose.

Common squeaks.

1. Constant velocity universal joint abnormal sound: Constant velocity universal joint is commonly known as ball cage, and its main function is to transmit power and complete steering. If the constant velocity universal joint is seriously worn, and the vehicle emits abnormal noises such as "quack, quack, quack" while driving, you only need to confirm that the abnormal sound is in **, and then replace the constant velocity universal joint to solve it.

2. Abnormal sound of wheel bearing: The function of wheel bearing is to connect the vehicle and tires. Regardless of the size of the tire, the vehicle-to-tire connection relies on a small hub bearing.

If the hub bearings are damaged, the tires can deviate or even fall off. When the vehicle is moving, it emits a continuous abnormal sound similar to a "buzzing sound".

3. Abnormal sound of exhaust pipe: abnormal sound of exhaust pipe is generally caused by rupture or leakage of exhaust pipe. When the vehicle starts, it makes a "poof" sound.

It can also be caused by damage or blockage of the three-way catalytic converter. Its function is to purify the exhaust gas and reduce noise at the same time. If the damage cannot achieve the effect of noise reduction, abnormal noise is inevitable.

Loose chassis generally occurs in older cars, when the car is driving in bad road conditions, the steering wheel will feel unstable, the bottom of the car will also come out of the abnormal sound, usually the old driver can feel the overall a little loose, when encountering such a situation, it means that the chassis may be loose, and the reasons for this situation are divided into several, only by understanding the reasons, can we better prevent this problem from happening.

The first reason is the aging of rubber parts, we all know that the elasticity of rubber is particularly good, which can buffer the friction between parts and reduce noise at the same time. However, this kind of thing has a lifespan, and it will age after a long time, and the elasticity is not as good as before, so the buffering capacity will decrease, resulting in abnormal noise in each part, so it is necessary to check these rubber parts regularly and replace them in time.

The second possibility is the reason for the shock absorber, the main role of this part is to inhibit **, when the car is driving in the dustpan section, it will have an impact with the road surface, and the shock absorber can well ensure the smoothness of the car, if the shock absorber is damaged, there will be a scoop phenomenon, so that the chassis is loose, so usually check the shock absorber, if there is a leakage to repair in time.

The third is the clearance of the parts, that is to say, the ball head may be loose, this part is like the joint of the human body, if the ball head is loose, there will be a large gap between the lever and other connected parts, if the gap is too large, when crossing some dustpan roads, the screws between the subframe and the suspension will be loose, then the chassis will become loose, so usually check these two parts.

Thank you for adopting.

Causes of the creaking of the car chassis:

1. There is a problem with the rubber sleeve of the balance bar. The phenomenon is: when the vehicle passes over uneven roads, the chassis will have abnormal noise.

The balance bar is also called the anti-roll bar and the stabilizer bar, and there are two buckles on the balance bar, and the buckle is the rubber sleeve of the balance bar. It is cold in winter and hot in summer, and with the erosion of soil and dust, it will become harder and harder after aging. When the vehicle passes through uneven road surface, the height of the left and right wheels is inconsistent, which will produce a creaking noise;

2. There is a problem with the brake pads. The phenomenon is: there is an abnormal sound under the front wheels, especially when the steering wheel is played.

Judgment method: When it rings, step on the brakes and see if it still rings. If it doesn't sound, it can be basically determined that there is a problem with the brake pads (there is also a song that may be a problem with the outer cage);

3. There is a problem with the connection between the suspension and the shock absorber. If the chassis creaks while the car is moving, this is most likely the cause. Judgment method:

After the vehicle is turned off, press the suspension part of the body to make the body shake up and down, and at the same time listen carefully to the abnormal sound, you can determine which part of the problem is;

4. Because you can't see the real car, you can't have an accurate judgment, such as the abnormal sound of the wheel bearing, the deformation of the shock absorbing spring, the aging or abnormal wear of the shock absorbing pressure bearing, etc., which will lead to the abnormal sound of the automobile chassis.

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Causes of abnormal noise in automobile chassis: 1. The abnormal noise emitted by the vehicle at the beginning is usually a suspension system failure, which may be caused by loose or damaged engine stands; 2. The abnormal noise emitted by the vehicle when steering may be the fault of the steering system and the suspension system, because the vehicle tilts the vehicle during the steering process, deforms the suspension system, and also participates in the movement; 3. The abnormal noise emitted by the vehicle when driving in good road conditions may be the fault of the braking system components, or it may be caused by the loosening or wear of the braking system components, the brake drum is out of circle or the brake disc plane is uneven; 4. It may also be a problem with the bearing between the vehicle connection and static, if it is a bearing problem, the driver can distinguish it with a little brake, if the vehicle does a uniform motion with a brake sound, it is a problem with the bearing.

The chassis of the car creaks, and there are several possibilities:

1.There is a problem with the rubber sleeve of the balance bar. Phenomenon: When a car passes over an uneven surface, the chassis makes a noise.

Equalizer bars are also known as anti-tilt bars and stabilizer bars. There are two buckles on the balance bar, and the rubber sleeve of the balance bar is inside the buckle. Cold in winter and hot in summer, coupled with soil and dust erosion, will become harder and harder as it ages.

When a car passes over uneven roads, the height of the upper and lower wheels is inconsistent, resulting in a creaking noise.

Solution: Replace it. This part is not expensive, but it is very troublesome to replace, and most people are basically reluctant to replace it.

This thing has nothing to do with security. If it doesn't work, put up with it. Another way is to buy WD40 (High Efficiency Silicone Lubricant), but not sure how effective it will be.

It is said that it can only be managed for a month.

2.There is a problem with the brake pads. Phenomenon: There is a noise under the front wheels, especially when playing the steering wheel. Judgment: When it rings, step on the brakes and see if it still rings. If it doesn't ring, you can basically determine that there is a problem with the brake pads (there is also a possibility that there is a problem with the outer cage).

Solution: Replace the brake pads.

3.There is a problem with the connection between the suspension and the shock absorber. If the chassis creaks when the car is moving, this is probably the reason.

Judgment method: After the car is turned off, press the top of the suspension part of the body to make the body shake up and down. At the same time, listen carefully to the noise, you can judge that there is a problem.

Since you can't see the actual car, you can't make an accurate judgment. For example, the noise of wheel bearings, the deformation of damping springs, the aging or abnormal wear of damping pressure bearings, etc. Basically affects the noise of the chassis of the car.

It is recommended to go to a 4S shop or a professional auto repair shop to let the technician conduct a test to determine the problem so that it can be repaired symptomatically.

Finally, () Bian Xiao is honored to answer for you, about the reason for the crunch of the car chassis? I have some opinions on this issue, and I hope you can find it helpful after reading it! If necessary, Bian Xiao is here waiting for your visit.

The reason for the squeaking sound of the automobile chassis: it may be that the claw pad of the engine is installed in a dislocation, which causes some components to resonate or shake when working, and the friction between two adjacent parts, of course, it is not excluded that it is caused by the abnormal sound caused by the damage of some parts.

Various possible causes of abnormal noise in the chassis of a car.

1. Abnormal sound of disc brakes.

Features: When the vehicle is driving at a low speed on a flat road, it makes an intermittent and irregular "rattling" sound on the axle.

Reason: This is due to the damage, deformation and falling off of the brake shoe support plate, vibration damping spring plate or guide plate of the disc brake, which increases the gap between the brake shoe and the brake caliper support frame, and makes a sound when it hits each other. You can go to the repair station to repair the deformed parts and replace the parts that have fallen off.

Second, the front suspension ball head abnormal sound.

Features: When the vehicle is driving on the undulating road surface in a low-speed gear, the front axle part emits an uninterrupted "click" sound, the worse the road quality, the louder the sound, and the sound intensifies with the increase of speed.

Reason: The gap between the ball head and the ball head seat becomes larger, and the looseness is severe. Because the ball head seat is a sealed structure and cannot be removed, it can only be replaced at the repair station in this case.

Three. Abnormal noise of the front wheel shock absorber.

Features: On flat roads, you can hear the "cooing" of the front of the vehicle, which is intensified when turning sharp corners.

Cause: Vehicles are often driven on bad roads and are not properly maintained, resulting in oil leakage and damage to shock absorbers. Depending on the severity of the damage, it will need to be repaired or replaced.

Fourth, the transmission shaft universal joint abnormal sound.

Features: If the front drive constant velocity joint is faulty, in the vehicle in motion, especially when cornering or accelerating sharply.

Reason: The abnormal sound of the constant velocity gimbal is due to the excessive clearance of the gimbal or the issuance of cards. The main reason for the abnormal sound of the universal cross shaft is that there is no lubrication device or the maintenance is not timely. In this case, you should go to the workshop to apply grease or repair.

Photo by Li Caiying of Pacific Automobile Network).