Many people may have a misunderstanding about four-wheel alignment, or they may confuse the concepts of dynamic balancing and four-wheel alignment. They think that it must be done after reaching a certain mileage or changing tires. This is actually true. Wrong. Four-wheel alignment is a maintenance item and generally does not need to be done if there is no problem. Now let me talk about the four-wheel alignment that must be done when the vehicle has problems while driving.
What is four-wheel alignment?
Because the four wheels of the vehicle, the steering mechanism (the assembly connected to the steering wheel, which is part of the suspension system) and the front and rear axles (the power of the front and rear wheels The installation between the transmission shaft (which is also part of the suspension system) has a certain relative position. This position is a standard value established by the manufacturer. Adjusting the installation back to this position is four-wheel alignment.
Why are there relative installation positions:
In order to avoid this problem becoming more difficult to understand, let me briefly explain that in fact, the wheels of the car are not installed perpendicular to the ground. There are "camber angles" and "toe angles." Next time you maintain the car, when the car is lifted up on the stand and the wheels are off the ground, you can observe from directly behind and in front, and you can still see it.
A normal car has a "splayed foot", so what are the functions of the "camber angle" and "toe angle"? In one sentence, it can be summarized as: eliminating harmful moments in vehicle driving and forcing the vehicle to travel in the straight direction. This is why when the vehicle is moving, there is always a backing torque on the steering wheel. This is the function of "camber angle" and "toe angle". But is the car's "splayed feet" outward or inward? What's the angle? Each vehicle has different parameters, and regular adjustment of these parameters (that is, four-wheel alignment) is necessary for the service life and safety of the vehicle.
Then here comes the problem! When is it necessary to do a four-wheel alignment?
1. The vehicle is deviating and cannot keep driving in a straight line
First of all, the most common thing is when it is discovered that the vehicle is deviating, that is, the car will involuntarily deviate to the left or right. Constantly adjust the steering wheel to keep the car traveling in a straight line. In addition to being annoying, this situation is also very dangerous. If you don't pay attention, you will run into other lanes. However, one more thing needs to be said here: misalignment is not necessarily a problem with four-wheel alignment. For example, inconsistent tire pressure on the left and right tires can also cause misalignment, so we have to analyze the specific problems in detail.
2. Tires are wearing eccentrically
We generally recommend checking the wear of tires after driving 20,000 kilometers or 1 year. If eccentric wear occurs, it is commonly known as "tire chewing" , it means that a four-wheel alignment is needed.
3. Chassis and suspension damage caused by accidents
Four-wheel alignment is also required for chassis and suspension damage caused by accidents. In addition to these common situations, when the car is drifting, the steering is unstable or overweight, and the suspension system parts are abnormally worn, it may be a four-wheel alignment problem.
Four-wheel alignment steps: pre-alignment inspection, data inspection, alignment adjustment
Pre-alignment inspection: First, the sizes of the four tires must be the same; in addition, subtle differences Also take into consideration, such as tire pressure, adjust the tire pressure in place according to the standard (the tire pressure standard is found on the inside of the fuel tank cap); there are also more subtle inspections, the tread depth on the table needs to be measured, and the tire tread depth on the coaxial The maximum deviation cannot exceed 2mm. If the conditions are not met, the relevant tires must be replaced as appropriate. Then there is the suspension system, which needs to ensure that the chassis is in a healthy state, and finally the unloaded state. This seems to be the most easily overlooked link. It is the same everywhere, and no one pays attention to it, but we must ensure that the vehicle is in an unloaded state and be prepared. Tires and vehicle tools should be placed in their respective locations.
Data inspection: After completing the inspection, the vehicle can be parked on a professional four-wheel alignment platform. After lifting to a certain height, ensure that the sensor is within the signal range of the transmitter. At the same time, after stopping the vehicle, put the gear in the neutral position, adjust the steering wheel and wheels until they are in a straight direction, and release the handbrake to move the vehicle in the next adjustment. Then install the sensor securely to ensure that the sensor and receiver are not blocked. Finally, move the vehicle in the directions shown on the computer to further correct and check whether there is any slack in the suspension connecting structural parts.
Positioning adjustment: Relying on data, the four-wheel positioning data of each tire is adjusted accordingly according to the degree of deviation. After debugging, the four-wheel positioning is not completed, and the repair needs to be verified through actual road driving test runs. Is it valid?
Then the problem comes again? So where is the most cost-effective place to get a four-wheel alignment? First of all, the most important thing when doing four-wheel alignment is that the vehicle wheels and other related parameter values ??must be accurate. Therefore, when we do four-wheel alignment, we must go to repair shops whose repair quality can be trusted. For example, 4S stores, but 4S stores generally charge more expensive fees. The cost of a four-wheel alignment is about 300 yuan, or even higher. You can also go to some brand tire service shops for four-wheel alignment calibration. The fees are relatively low. The cost is about one hundred yuan per time. Generally, the quality of repairs is not a problem.
It should be noted that not all repair shops with four-wheel alignment equipment can perform four-wheel alignment. The four-wheel alignment parameters of each car are different. Only those repair shops with corresponding parameter values ??can perform four-wheel alignment on the car. , otherwise it is recommended to go to a 4S store to do it.