The role of the shock absorber and the performance of judging the broken shock absorber of the car

Automobile shock absorber is an important part of automobile suspension system, its function is to restrain the spring rebound shock to the absorption of vibration and deformation, and absorb the impact of the road. It directly affects the ride comfort and maneuverability of the vehicle, which will affect our driving safety.

The role of shock absorbers

From the name of the shock absorber, it seems that the vibration of the vehicle is mainly absorbed by the shock absorber, in fact, it is not. The energy generated by the vibration of the vehicle through the uneven road surface is mainly absorbed by the spring, and the spring will produce a rebound shock after absorbing the shock, at this time, the shock absorber is used to slow down the shock caused by the spring.


When the shock absorber fails, the car will not bounce on the road because of the bouncing energy of the shock absorber spring, which affects the stability and comfort of driving. Simply put, the main purpose of the shock absorber is to inhibit the bounce of the spring and quickly eliminate the bounce of the body.

We usually say that the car vibration and soft and hard, refers to the damping force, the greater the force, the harder the shock absorber. If the shock absorber is too soft, no spring can quickly absorb the vibration, the body will jump up and down between the tire and the ground, the adhesion is not good, but the comfort of the car will be better, the general family car tends to use soft shock absorber shock absorber; If it is too hard, it will bring too much weight. The resistance spring prevents the buffering function, but the adhesion between the tire and the ground is better, so the damping of some sports cars or SUVs is very hard.

It should be noted that the shock absorber only plays the damping role of the suspension spring, but does not support the body, so the body has no relationship with the shock absorber. The real support of the body is the suspension spring, some cars for their driving performance, modified high or low, are changing the length and elasticity of the suspension spring, plus the corresponding shock absorber. If the shock absorber had no spring, the car would lie on the ground and not move.

Automotive shock absorbers are also vulnerable parts, with the extension of use time, there will be performance degradation or loss of function. How to tell if the shock absorber is damaged? General shock absorber damage after the following failures: (如何判断减震器是否损坏?一般减震器损坏后有下列故障:)

1.Shock absorber leakage. The outer surface of the ordinary shock absorber is dry and clean. If the oil seeps, the hydraulic oil in the shock absorber leaks from the upper part of the piston rod. In this case, the shock absorber basically fails.
2.When the car crosses a bumpy road or speed bump, the wheel makes a “pop” sound, indicating that the shock absorber on the wheel is ineffective or ineffective.

3.When the car turns, the roll of the car body increases significantly, and even sideslip will occur in serious cases. This is mainly because the damping force of the shock absorber is too small to effectively inhibit the compression of the spring.

4.After driving on rough roads for some time, we felt the temperature of the shock absorber housing with our hands. Under normal conditions, the shock absorber housing is warm. If the shock absorber housing is cold, it means that the shock absorber has been damaged.

5.when the car comes to a stop, when we press a corner of the body and release it, the body will bounce back under the action of the spring force. If the rebound is quickly stable, it means that the shock absorber is good; If the shock absorber repeated several times before stopping, this indicates that the damping effect of the shock absorber is slightly worse.

Before determining a problem or failure of the shock absorber, check the shock absorber for oil leakage or traces of old oil leakage.The oil seal washer and seal washer are broken and damaged, and the cylinder head nut is loose. Possible damage to oil seals and gaskets. A new seal should be replaced. If the oil leak cannot be eliminated, the shock absorber should be pulled out. If it feels like there is a hairpin or a different weight, further check that the gap between the piston and the cylinder is too large, regardless of whether the piston link shock absorber is bent, the piston link surface and the cylinder are scratched or stretched. If there is no oil leakage in the shock absorber, check for damaged, broken, broken or disconnected connection pins on the connection rods, connection holes and rubber shock absorber bushings. If the above check is normal, the shock absorber should be further disassembled to check that the fit clearance between the piston and the cylinder is too large, whether the cylinder and the valve are sealed well, whether the valve disc and the seat are tightly fitted, and whether the shock absorber extending the NISH spring is too soft or broken, and the repair or replacement method should be taken according to the situation.In addition, the shock absorber will make a noise in the actual use of the fault, which is mainly due to the shock absorber and the leaf spring, frame or shaft collision, rubber pad damage or fall off and the shock absorber dust cylinder deformation, insufficient oil and other reasons caused by the cause should be identified and repaired.After the overhaul of the shock absorber, it should be tested on the special test bench. When the resistance frequency is 100, for example, the maximum resistance to the cal091 tensile stroke is 2156-2646n, the maximum resistance to the compression stroke is 392-588n, the maximum resistance to the Dongfeng truck tensile stroke is 2450-3038n, and the maximum resistance to the compression stroke is 490-686n. If there are no test conditions, we can also use the empirical method, which is to penetrate the lower end of the shock absorber ring with the feet on both ends of it, hold the ring on both hands and pull them back and forth 2 to 4 times. When pulled up, the resistance is very large, and when pressed down, it is not difficult to recover with tension compared to before repair. No sense of idling indicates that the shock absorber is basically normal.


Therefore, for the damaged shock absorber we should replace it in time, usually the coaxial shock absorber on both wheels should be replaced at the same time. In addition, the different damping effects of the two shock absorbers will lead to inconsistency between the left and right steering handles of the vehicle and the body roll, which not only affects the riding comfort, but also seriously affects the maneuverability of the vehicle, making the vehicle difficult to control. When changing lanes, overtaking and turning increases driving risk. So, don’t save money, just replace the damaged shock absorber. In addition, when the shock absorber is replaced, the parts related to wheel positioning are removed, so four-wheel positioning is required to prevent inaccurate wheel positioning. In daily use, it should be checked frequently, and the shock absorber should not be easily modified to avoid damaging the overall performance of the chassis suspension system.


Max Auto Parts ltd is the manufacturer of shock absorber and coil spring .

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Post time: Dec-12-2023