How do you know when the shock absorber damping force fails?

The damping characteristics of the Sachs shock absorber are closely related to the suspension type of the vehicle and the vehicle usage conditions. Usually, when the vehicle chassis uses leaf springs, the shock absorber is required to adopt a larger asymmetric damping characteristic design, that is, the tensile damping force is much larger than the compression damping force, as shown in Figure 2-10. The compression damping force is small, and this asymmetric damping design is completely determined by the vehicle chassis structure and characteristics. Due to the user's lack of understanding of the damping characteristics of the Sachs commercial vehicle shock absorber, it may cause misjudgment.

In addition, the damping force of the shock absorber is large when the piston moves at high speed and small when it moves at low speed. The damping force is even smaller during very slow extension and compression, and the user may think that the shock absorber has failed, resulting in misjudgment. However, this is a function of the shock absorber itself, and there is no need to replace the shock absorber.

Sachs recommends a method to determine if the damping force has failed: stretch it quickly with your hands, and if the damping is significantly greater than the compression damping by several times, the damping force is normal and does not need to be replaced. When the tension damping is similar to the compression damping, it means that the tension damping force has failed and needs to be replaced.

When users find that the vehicle vibrates abnormally, they may attribute it to the failure of the shock absorber. At this time, Sachs recommends first observing whether the shock absorber is leaking oil, and using the above method to simply determine whether the shock absorber has failed. If the shock absorber itself is not leaking oil and has not failed, it is recommended to check whether the shock absorber is installed correctly, or other factors cause abnormal vehicle vibration.