The situation of the wheel “eight” is familiar to many motorists, especially those who often operate the vehicle in bad roads. This phenomenon not only causes discomfort when driving, but also poses a direct threat to safety, as it violates the stability of management. The vibration of the steering wheel, beating in the body at high speeds and uneven wear of the tread are all clear signs that the geometry of the wheel is broken. Ignoring the problem can lead to failure of the suspension and steering elements.
The causes of the “eight” can be very different, ranging from a banal blow to the curb and ending with the production defect of a rubber or disk. Often, car owners sin on tires, forgetting to check the condition of the wheels, and vice versa. It is important to understand that even a minor beat progresses over time, turning into a serious malfunction that requires expensive intervention. In this article, we will discuss in detail why the wheel becomes the eight, how to accurately diagnose the problem and what methods exist to solve it.
Mechanical damage to wheel discs
The most common reason why the wheel begins to “eight” is the deformation of the disk itself. Metal alloys, from which wheels are made, although they have a certain plasticity, but have a limit of strength. With a strong impact on a hole, pothole or when hitting a high curb, a violation of geometry occurs. Aluminum discs in this regard, more fragile than steel - they are prone to cracks and chips, whereas steel is often just crumpled, which sometimes allows you to restore the shape.
However, it is not always the cause of extreme shock. The cumulative effect of constant driving on broken roads also leads to gradual curvature. The disc can receive a radial beat (eight) or an axial beat (egg). In the first case, the wheel hits up and down when rotating, in the second - from side to side. If you notice that after passing through deep puddles or pits, the car began to move aside or vibration appeared, the first thing you need to check is the geometry of the disks.
⚠️ Attention: Operation of a car with a deformed disk is prohibited. This leads to depressurization of the tire, loss of pressure and a sharp deterioration in traction, especially in cornering.
Diagnosis of the disc is best carried out on a specialized stand, where the wizard will determine the exact values of the beat using the indicator. You can try to visually examine the disk by scrolling the wheel, but it is difficult to notice small deformities with the eye. If the disk is "led", you can try to straighten it, but only if it does not have cracks. For alloy wheels, the editing procedure is more complicated and requires heating, which is not always safe for the metal structure.
Can you edit cast discs?
Correction of cast discs is possible only in the absence of cracks. The technology includes heating the damaged area and restoring geometry to the hydraulic press. However, after this procedure, the disc loses some of its strength, and its use on the front axle is not recommended.
Defects and features of car tires
If the discs are all right, the next "suspect" is the bus itself. Rubber is an elastic material, but it is also subject to wear and damage. One of the common causes of the beating is hernia on the sidewall. It occurs when the tyre cord is stretched or torn, and a characteristic bloating is formed under air pressure. This wheel eight is very strong, and it is absolutely impossible to ride it.
Also, the cause can be uneven wear of the tread. This often happens if the car has been standing still for a long time, or if there have been problems with falling-down. Spotted wear creates the effect of a “step”, which when the wheel is rotated is perceived as a beat. Another option is to split the tire frame inside. Externally, the tire may look whole, but inside there is a detachment of the layers of the cord, which leads to the appearance of internal deformations.
Production marriage is less common, but you should not discount it. This can be an uneven overlap of layers of cord or a violation of centering during vulcanization. In such cases, the wheel may be perfectly round, but its center of gravity is shifted, causing a static or dynamic imbalance perceived as an eight.
When buying new tires, be sure to conduct an initial balancing and inspect the wheels on the stand. This will allow you to identify the factory defect before you start operation.
Problems with balancing and fastening
Sometimes what the driver thinks is an eight is actually a big wheel imbalance. If the loaders glued or stuffed on the disc have departed, or if errors were made during the previous balancing, the wheel will beat. Dynamic imbalance It is manifested by vibration of the steering wheel at high speeds (usually from 80 to 120 km / h). Static imbalance causes the wheel to bounce.
Equally important is the correct fit of the wheel on the hub. If the landing plane of the disc or hub is contaminated with rust, dirt or has bullies, the wheel will be skewed. Even a minimal grain of sand or oxidation can produce a beat of several hundredths of a millimeter, which at speed will turn into a tangible vibration. Fixing bolts also play a role: if they are twisted with different forces or have different thread lengths, the disc can skew.
- 🔧 Landing plane cleaning: Be sure to clean the contact point of the disc and hub with a metal brush before installing the wheel.
- ⚖️ Quality balancing: Use only modern machines with beat optimization function to minimize the amount of loads.
- 🔩 Puff moment: Twisting the bolts with a dynamometer key, observing the factory values of the tightening moment for your car model.
☑️ Post-tyre inspection
Failure of suspension and steering components
It happens that the wheel and the disc are completely intact, and the vibration and beat are preserved. In this case, the reason lies in adjacent nodes. Worn-out solar blocks, ball supports or steering tips create backlashes. When rotating, the wheel, devoid of rigid fixation, begins to walk, creating the illusion of an eight. This is especially noticeable when braking or on uneven roads.
The sling bearing is another critical element. When it is destroyed, an axial backlash appears, and the wheel begins to dangle. This causes a very strong beat, which grows proportionally to the speed. If you do not replace the bearing in time, the hub itself may collapse or jam the wheel. It's worth checking out. driveshaft (on front-wheel drive cars): wear of the SRUS or curvature of the shaft itself is often transmitted to the wheel.
| Element | Symptom of malfunction | Method of verification |
|---|---|---|
| Stack bearing | The hum, increasing with speed, the lumpy | Hand-wheel swing (top-bottom) |
| Ball-pillar | Knocking on the bumps, sideways. | Lift, backlash check mount |
| Steering tip | Steering, knocking. | Wheel swing (left-right) |
| Drive shaft | Acceleration vibration | Visual inspection of anthers and backlash |
Diagnosis: how to determine the source of the beat
To effectively eliminate the problem, you need to know the source. The simplest method is a visual inspection on the go. Take the car to a flat platform, accelerate and pay attention to the nature of the vibration. If the steering wheel is shaking, the problem is most likely in the front wheels. If the body or seat vibrates, the “eight” on the rear wheels. However, this method is subjective and does not give accuracy.
A more reliable way is to use a diagnostic stand in a tire workshop. The wheel is removed, cleaned and installed on the balancing machine. A special probe indicator shows the magnitude of radial and axial beats. If the beating gives the disk, the indicator will fix it. If the disc is flat, but the wheel assembled (with a tire) beats - then the problem is in the rubber. It is also important to check the beat on the car itself, lifting it on the lift and scrolling the wheel manually, watching the gap between the tire and the stationary suspension element.
Do not forget about the simple but effective method of “permutation”. Change the suspicious wheel with another (for example, from a spare or a nearby one). If the vibration has moved with the wheel, we look for a defect in it. If the vibration pattern remains on the same axis or in the same corner of the car, dig deeper into the suspension.
⚠️ Attention: Never try to straighten the disk with a sledgehammer on the side of the road. This is guaranteed to lead to the final destruction of the metal structure and the impossibility of further repair.
Accurate diagnostics on professional equipment saves money by allowing you to replace only a defective element (a tire or a disk) rather than buying a new kit.
Remediation and prevention
If the cause is found, begin to eliminate. Deformed steel discs rule on a hydraulic machine. Alloy wheels only rule in the absence of cracks, using hot rolling technology. If the disc is not repairable (too severe deformation or cracks), it must be replaced. Riding on the "pancake" is life-threatening.
With tires everything is stricter: hernias, cuts of the cord and stratifications are not repaired. You have to throw that rubber away. If the reason is uneven wear due to a violation of the descent-breakdown, then after replacing the rubber, you must visit the adjustment stand for the angles of the wheel installation. Balancing should be done at each seasonal change of tires or when vibrations appear.
- 🛡️ Careful driving: Avoid a sharp entry into pits and hitting curbs, especially on low-profile rubber.
- ❄️ Seasonal: Do not use summer tires in winter, as they tan and are more easily damaged by impacts.
- 🔍 Regular inspection: Once a month, check the pressure in the tires and visually examine them for bloating.
Prevention is the best way to avoid problems. Using discs of the right size and departure, compliance with the speed mode on bad roads and timely maintenance of the suspension will prolong the life of your wheels. Remember that the wheel is the only element of the car’s contact with the road, and its serviceability directly affects your safety.
Does the pressure in the tires affect the eight?
Insufficient pressure makes the sidewall of the tire soft, which increases the likelihood of getting a hernia on impact. The pumped tire becomes rigid and transfers all the beats to the disc, increasing the risk of its deformation. Keep your blood pressure normal!
Frequently Asked Questions (FAQ)
Can I drive if the wheel is a little eight?
It is possible to drive, but extremely undesirable and dangerous. Even a small “eight” creates a constant vibration that destroys the bearings of the hub, the elements of the steering and suspension. In addition, it reduces traction and increases the braking distance. If the beating is strong (more than 2-3 mm), the operation of the car is prohibited.
How much does it cost to edit the disc?
The cost depends on the type of disk (stamped or cast) and the degree of damage. Editing a steel disc is usually cheaper and takes less time. Cast discs are more expensive and more difficult to rule. On average, the price varies from 500 to 2000 rubles per disk, but it is better to clarify the current prices in local workshops.
Will there be eight if you don’t balance for a long time?
The lack of balancing does not make the disk curve. However, the imbalance causes an uneven load on the suspension and tire, which leads to spotty wear of the tread. This wear can already be perceived as a beating. In addition, the cargoes can fly away, and the vibration will increase.
How to understand: a hernia in a tire or a curved disk?
Take off the wheel and inspect it separately from the car. Scroll the tire and the drive. If the "hump" moves along with the tread pattern, it is a hernia in the tire. If the bulge remains in one place relative to the disc (metallic part) when the rubber is rotated, the disc is deformed. The stand will show you.