When the shock absorbers are faulty, the car sways strongly when passing over bumps, lurching during maneuvering, leaning forward during acceleration and braking, and the braking distance is increased. Such automobile behavior affects both its drivability and service life of other suspension parts. To reduce your repair costs you should pay attention to obvious and hidden signs of defective shock absorbers.
Signs of defective shock absorbers
For visual inspection you must know, what are the symptoms of a faulty shock absorber. It is worth checking them when at least one of the five symptoms appears:
- Swaying during braking and acceleration. If the car swings more than twice during braking, it is a sign of shock absorbers failure. When they are serviceable, the car should swing back no more than once, after which the shock absorber dampens oscillatory movements.
- Roll during maneuvering. When entering a turn, the body should not sway in the transverse plane. If it is so — the shock absorbers are defective.
- Deteriorated control of the road. When the steering wheel is set in a straight position, the car constantly steers sideways. You have to steer constantly to align the driving trajectory.
- Discomfort while driving. It can be manifested in different ways. In particular, some drivers and/or passengers can suffer from «seasickness» while driving for a long time, because of car's swaying. This effect is a typical symptom of defective rear shock absorbers.
- Increased braking distance. This factor is caused by the same sway during braking. When the shock absorber stops damping vibrations, then during braking the car periodically lowers and lifts the front part of the body. Because of this the load on the front wheels is reduced, which reduces the effectiveness of braking.
Visual indicators of bad shock absorbers are:
- Appearance of leaks on the body and rod. In particular, this is due to wear on the packing (seal) and/or the shock absorber rod.
- Wear on the silent blocks. If the shock absorber works hard, increased forces will be transmitted to the silentblock, which will lead to its considerable wear and failure. Therefore, when diagnosing shock absorbers, it always makes sense to check the condition of the silent blocks as well.
- Uneven wear of tires. Usually they wear more on the inside and less on the outside.
What a faulty shock absorber affects
The use of worn shock absorbers can not only cause discomfort while driving, but also cause a real danger while driving. So, the possible problems associated with a faulty shock absorber are:
- Reduced traction of the wheels with the road. In particular, the grip will have a variable value when the car is rocking.
- Increased braking distance, especially on vehicles with an anti-lock braking system (ABS).
- Possible incorrect operation of some electronic systems of the car, such as ABS, ESP (directional stability system), and others.
- Deterioration of vehicle controllability, especially when driving at high speeds.
- Occurrence of «aquaplaning» when driving on a wet road at low speeds.
- When driving at night, the constant swinging of the car's front end may cause the headlights to dazzle oncoming drivers.
- Discomfort while driving. It is especially evident when driving long distances. For the driver, it threatens with increased fatigue, and for people prone to «seasickness», it is dangerous with motion sickness.
- Increased wear of tires, rubber bushings, silent blocks, bumpers and springs. and other elements of the car suspension.
Causes of shock absorber failure
What can cause a shock absorber to fai:
Torn shock absorber duster
- Aging of the shock absorbing fluid (oil). Like other technological fluids in the car, the oil in the shock absorber gradually gains moisture and loses its operational properties. Naturally, this causes the shock absorber to start working stiffer than it did before. However, it is important to understand that fluid aging does not happen overnight, with the exception of a torn seal on the shock absorber housing.
- Torn packing. Specifically, the seal on the piston and inner walls of the operating cylinder. The oil seal can be torn due to external factors or simply in the process of aging. It, as well as any rubber seal, with time becomes stiff and starts leaking fluid. This causes oil leakage from the shock absorber, as well as the ingress of moisture from the outside into the oil, which leads to the deterioration of its characteristics.
- Deformation of the valve mechanism plates. This process is also natural and occurs on a constant basis, though at different rates. Thus, the rate of deformation depends on two main factors — the quality of shock absorber (quality of metal plates) and the operating conditions of the machine (of course, that a significant shock load leads to premature deformation).
- Failure of silent blocks. They wear out due to natural reasons, lose their elasticity and performance. Repair of these nodes is practically impossible, so when they fail, you simply need to replace them (if possible, or replace the entire shock absorbers).
How to determine if a shock absorber is defective
There are three methods of how to check shock absorbers.
The simplest one is to rock the car body.
- It is necessary to rock the front and the rear part of the body in turn to determine which shock absorbers are out of order, front or rear (you need to replace them in pairs). It is necessary to rock hard, but not to bend the body elements. Having reached maximum possible amplitude stop swinging a car and look at its further oscillations.
If the shock absorber is good, the body will rock once (or a half), then it will calm down and stay in its original position. In the case if the shock absorber has a malfunction, it will sway several times.
However pay attention that on a car with multilever suspension, it will damp the arising vibrations even with defective shock absorbers. Therefore, with the help of body rocking, by and large it is possible to determine two boundary conditions — complete failure, or its jamming during operation.
- If the shock absorber / shock absorbers are faulty, then while driving the driver will feel that the car walks sideways and will need to steer constantly to keep it on a straight track.
During acceleration and braking the car will sway. The same situation is with lateral inclinations of a body. It is not necessary to accelerate to a significant speed, the city speed mode will be quite suitable for checking. In particular, at speed of 50… 60 km/h, you can do a sharp acceleration, braking, a zig-zag.
- When diagnosing a shock-absorber problem, it is necessary to drive a car to the observation pit or to an elevator. You can, of course, dismantle shock absorber, but it may take much time and effort. During the inspection it is necessary to check the presence of oil leakage on the shock absorber body.
When inspecting it is necessary to pay attention to the nature of the wear and tear of the tires. Often with broken shock absorbers they wear unevenly, as a rule, the main wear goes on the inner part of the tire. There may also be individual bald patches of wear on the rubber.
When to change the shock absorber
It is necessary to understand that regardless of the quality of the shock absorber, as well as the operating conditions of the machine, wear and tear of this node occurs constantly. Accordingly, it is also necessary to check their condition all the time. Most producers of shock absorbers from the middle price category recommend checking them every 12,500-19000 miles. As for replacement, usually the shock absorber is significantly worn out after approx. 50...62 thousand miles.
In order to make shock absorbers serve for a maximum length of time you should follow these recommendations:
- Do not overload the car. In the manual for any car it is directly indicated its maximum load capacity. You should not overload the car, because it is detrimental for its various components, including the engine and suspension elements, particularly shock absorbers.
- Allow to come to the working mode. When driving a car in the cold season (especially at considerable frosts) try to go the first 1000… 2000 feets at low speed and avoid bumps. This will allow the oil to warm up and flow out.
What does a broken shock sound like?
You will hear knocking and clunking sounds (metal-to-metal hits).
How much does it cost to change shock absorbers?
You can spend about 250 to 500$ on replacement of a pair of shock absorbers.
Can you drive with a faulty shock absorber?
No, you shouldn't drive a car with worn out shock absorbers, as well as with broken coil springs.