How to distinguish abnormal noise of shock absorber？

The abnormal noise of shock absorber is divided into mechanical friction noise and hydraulic noise.

Mechanical friction noise: divided into internal and external noise.

Internal noise:

1) Due to the looseness of the internal parts of the shock absorber, noise is generated and it must be replaced.

2) Due to the high loading position, the support ring inside the shock absorber collides with the guide and makes a knocking sound, which must be replaced.

3) Due to the low loading position, the shock absorber cover collides with the outer tube mouth and makes a knocking sound, which must be replaced.

4) When the vehicle is moving, the dust cover rubs against the outer tube, the spring rubs against the outer tube or the dust cover, and a knocking noise is generated, which must be replaced.

Causes of collision:

a) The dust cover is deformed by impact and rubs the outer cylinder, as shown in Figure 2-13; it needs to be replaced.

b) The roundness of the dust cover port is deviated, rubbing the outer cylinder, and replacement is required.

c) The road condition is too bad, and when the vehicle is severely tilted, there is lateral mechanical collision noise. When the vehicle is driving on a normal road, the mechanical collision noise disappears. Generally, it does not need to be replaced.

External noise:

Noise caused by interference between the shock absorber and other vehicle parts. If the shock absorber is not damaged, the shock absorber does not need to be replaced. However, the interference must be eliminated to avoid further damage to the shock absorber. If the user finds that the vehicle makes noise while driving, it may be attributed to the shock absorber noise. If there is noise on one side of the vehicle, we recommend that the user swap the shock absorber on the quiet side with the shock absorber on the noisy side or replace the shock absorber of the noisy vehicle with the noiseless vehicle to confirm the source of the noise.

The noise caused by the loose connection between the shock absorber and other suspension parts is not a quality problem of the shock absorber.

There are three factors that cause hydraulic noise

1) Noise generated when the shock absorber oil generates damping force through the small hole throttling method.

2) Noise generated when the piston stopper hits the guide (generated when the stretching limit is reached).

3) When the vehicle is driving, the vibration generated by the shock absorber at a certain speed point coincides with the vibration frequency of the mechanical parts of the vehicle body, causing resonance and noise. The noise disappears during normal driving. The above hydraulic noise is normal when the vehicle is driving. No replacement is required.