Cause of noise generated by shock absorber

"Shock Absorber will produce noise in actual use, mainly caused by shock absorber and plate spring, frame or shaft collision, rubber pad damage or fall off, shock absorber dust cylinder deformation, insufficient oil and other reasons. The cause should be identified and fixed. After driving 10km on a road with poor road conditions, the owner can stop the car and touch the shock absorber shell with his hand. If it is not hot enough, there is no resistance inside the shock absorber and the shock absorber is not working. Appropriate lubricating oil can be added and then tested. If the shell is hot and the shock absorber is short of oil, add enough oil. Otherwise, shock absorbers are ineffective."