Suspension repairs are the most common repairs, although struts and shock absorbers will wear out over time. The degree of shock absorber wear depends on the following factors: the condition of the road surface, vehicle load and how the vehicle was used.
During of the car operation, you can see the wear of the suspension elements by changing the steering accuracy, braking efficiency and the appearance of extraneous noise. We’ll talk about signs of wear on shock absorbers and struts below.
Symptoms of bad shock absorbers
You can feel the front of the car quickly lean towards the road when you braking. This is one of the signs of wear on the shock absorbers and struts and these leads to an increase in the stopping distance.
The car sways when driving – this symptom will be pronounced when driving bumps in the road (bumps). Excessive rocking of the car indicates ineffective shock absorbers and struts. Shock absorbers do not damp bumps in the road and do not soften impacts when hitting bumps if they are wear. In this case, the shock absorbers must be repaired or replaced. This wobbling can result in uneven and frequent tire wear.
If the shock absorbers are working properly, then after the car hits a bump, the car should level out and stabilize, that is, stop swaying.
The Car Wobble Around Corners – wearing of the shock absorbers does not allow correct control of the displacement of the vehicle’s mass when cornering. In this case, you will feel a deterioration in the quality of management. Additional effort is required when turning the steering wheel, resulting in the feeling that you cannot controlling the vehicle as you would like.
If you notice your car is sags to back while acceleration – the rear of the car sags strongly while the acceleration, and the front part of car rises due to the acceleration impulse. Typically, it leads to motion sickness and increased wear on the rear suspension components.
There is vibration on the steering wheel – if you are driving on an uneven road, then vibration on the steering wheel is acceptable. And when you feel this kind of vibration when driving on a flat road, it indicates wear on the shock absorbers and steering stabilizer.
There are squeaks and knocks in the suspension – excess noise may appear as a result of metal-to-metal contact when the shock absorber is triggered when hitting bumps. This may indicate wear on the mounting components of the shock absorbers and struts.
Liquid leaks from the shock absorber / strut – the shock absorber is leaking as a result of wear of the seals, in which case the shock absorber does not work effectively.
How to choose a shock absorber
As mentioned above, the driving style influances directly to the wear of the shock absorbers. Therefore, the selection of shock absorbers must be carried out individually, taking into account various factors.
The types of shock absorbers for aggressive driving are completely unsuitable for drivers who like a calm and measured driving style. If you will have used the car for driving in the city, standard oil racks are fine. For tough and aggressive operating conditions, you need choose shock absorbers with enhanced rebound and compression.
Ensure that the technical and operational characteristics of the shock absorbers are consistent. Use the same types of shock absorbers at both the front and rear.
In order to avoid mistakes when select the shock absorbers, use the VIN number.
Characteristics of shock absorbers
Determination of the main parameters of the shock absorber is carried out by means of its hydraulic calculation. The figure shows the approximate characteristics of shock absorbers for trucks and cars.
In the course of compression and recoil in modern shock absorbers, forces develop (less in the compression stroke and more in the recoil stroke). They can be expressed as follows:
As can be seen from the curve, at a speed of 30 cm / s in this shock absorber, the bypass valves open during the recoil stroke, which limits the maximum fluid pressure, reduces the intensity of the increase in the force P.
Use the calculated power N, which corresponds to the speed of the shock absorber piston, and the last figure characterizes a very intense mode when choosing the main dimensions of the shock absorber. The power absorbed by the shock absorber can be calculated using the formula: