When to change the suspension springs
Automotive suspension includes a large number of parts, and all of them certainly play an important role in providing handling in motion, smooth ride and stability in corners. But perhaps the key element of this system is the springs.
Along with springs and torsion bars, they are among the elastic components of the suspension. The springs protect the powertrain, body and other components of the machine, significantly reducing the adverse impact of bumps when driving over uneven road surfaces. In addition, they support the weight of the body and provide the necessary ground clearance (clearance). In general, this is one of the details that make driving comfortable and safe.
When the wheel hits a bulge in the roadway, the spring is compressed, and the wheel is lifted off the road for a moment. Due to the elasticity of the spring on the body, the impact is transmitted significantly softened. then the spring expands and seeks to return the wheel to contact with the road. Thus, the grip of the tire with the road surface is not lost.
However, in the absence of a damping element, the springs would continue to swing for a rather long time and in many cases would not have time to decay until the next uneven road. This means that the car would swing almost constantly. In such conditions, it is difficult to talk about satisfactory handling, comfort and driving safety.
Solves this problem, which serves as a damper that dampens vibrations. Due to the viscous friction in the shock absorber tubes, the kinetic energy of the rocking body is converted into heat and dissipated in the air.
When the spring and damper are balanced, the car rides smoothly and handles well without undue driver fatigue. But when one of the components of a pair is worn out or defective, the balance is disturbed. A failed shock absorber cannot effectively dampen the inertial oscillations of the spring, the load on it increases, the amplitude of the buildup increases, adjacent coils more often come into contact. All this leads to accelerated wear of the part.
The spring also loses elasticity over time. In addition, the protective coating may be damaged, and corrosion will gradually begin to kill the spring. It happens that a fracture also occurs - most often a part of the coil breaks off at the upper or lower end. And then the increased load falls on the shock absorber, its working stroke increases, often reaches the limiter. Accordingly, the shock absorber begins to wear out at an accelerated pace.
Thus, springs and shock absorbers are closely related to each other, and the correct functioning of one of these components directly depends on the health of the other.
Loss of elasticity after a certain period of operation occurs due to the natural fatigue of the metal.
Another reason why this part becomes unusable is high humidity and chemically active substances, for example, those used in winter to fight ice and snow on the roads. These factors lead to corrosion and loss of elastic properties.
Regular overloading of the machine will also reduce the life of the springs. Such a mode of operation often leads to its turning point.
In addition, mechanical action negatively affects its durability - stones, sand, maximum compression, especially if it is accompanied by an impact, for example, when driving over an unevenness at speed.
Of course, it is worth once again remembering sloppy driving. However, a sharp manner of driving a car significantly reduces the resource not only of springs, but also of many other parts and assemblies.
Finally, another factor that affects the service life is the quality of workmanship. Despite the apparent simplicity of the spring, the process of its manufacture is very complicated. In production, special steel grades and special elastic paint coatings are used that can withstand repeated mechanical, thermal and chemical effects. The preparation of the spring rod, its winding, hardening and other stages of production must be carried out in strict accordance with the technology. This is the only way to get a product of good quality. How and from what cheap fakes are made, one can only guess, but it is better to stay away from them and not tempt fate.
You can navigate by several main signs that indicate the deterioration of these parts.
- Car sagging on one wheel. You can measure the distance from the arches to the ground and compare the results with those indicated in the repair documentation. But the difference is often visible to the naked eye. If the tire is not flat, then the spring is broken. Or a spring cup - in this case, welding is required. More precisely can be determined by inspection.
- The ground clearance has decreased or the car sags noticeably even under normal load. Compression travel is minimal. This is possible if the car is often overloaded. Otherwise, the point is metal fatigue.
- Extraneous sounds in the suspension, although there is no noticeable subsidence or signs of wear of the shock absorber. Probably a small piece broke off at the end of the spring. A deaf rattle in this case occurs due to the friction of the fragment and the remaining part of the spring between themselves. The situation in itself is not so terrible, but a broken piece can bounce anywhere and pierce, for example, a brake pipe, a tire, or damage some other suspension part. And it is possible that the one who rides behind you will be “lucky” and his windshield or headlight will be broken.
- Rust can be detected by visual inspection. It all starts with defects in the paintwork, then moisture does its job. Corrosion destroys the structure of the metal, making it weaker and more brittle.
- If you notice that it has become stiffer, and the shock absorber often taps due to limited travel, then in this case it is also worth diagnosing the condition of the springs.
Depending on the specific brand of car, operating conditions and the accuracy of the driver, the springs provide mileage from 50 to 200 thousand, it happens that even up to 300 thousand. The average service life is approximately 100 ... 150 thousand. This is approximately twice the resource of shock absorbers. Thus, every second scheduled replacement of shock absorbers should be combined with the installation of new springs. In this case, you will not need to pay separately for their replacement.
In other situations, it should be determined depending on the age and specific condition of the parts. In any case, they must be changed in pairs - on both sides of the axis. Otherwise, there will likely be a distortion due to differences in parameters and varying degrees of wear. Further, the wheel alignment angles will be disrupted and the tires will wear unevenly. As a result, the imbalance will worsen handling.
And do not forget to diagnose and adjust the wheel alignment (alignment) after the change.
When choosing to replace, proceed from the fact that the new part should be the same shape and size as the original. This applies to bore diameters and maximum outer diameter. At the same time, the number of turns and the height of the unloaded part may differ.
Installing springs of a different type, with different parameters and different stiffness can lead to unexpected consequences, and the result will not always please you. For example, springs that are too stiff can cause the front or rear of the car to ride up excessively, while springs that are too soft can cause a lot of roll in corners. Changing the ground clearance will disrupt wheel alignment and lead to increased wear of silent blocks and other suspension components. The balance of the joint work of springs and shock absorbers will also be disrupted. All this will ultimately negatively affect handling and comfort.
When buying, give preference to trusted manufacturers and. So you will avoid purchasing low-quality products or outright fakes. Among the manufacturers of high-quality springs and other suspension components, it is worth noting the Swedish company LESJOFORS, the German brands EIBACH, MOOG, BOGE, SACHS, BILSTEIN and K + F. From the budget one can distinguish the Polish manufacturer FA KROSNO. As for the popular manufacturer of auto parts from Japan KAYABA (KYB), there are a lot of complaints about its products. This is probably due to the large number of fakes. However, KYB springs are of good quality and buyers usually have no complaints about them.
