When You Need To Do Car Wheel Aligning

Under what circumstances do four rounds of positioning?

1, the driving performance of the vehicle has been affected (the driver is the most direct experience of deviation, not the direction of the wheel can also be considered a round)

2, due to accidents caused by damage to the chassis and suspension

3, the tire wear abnormalities (but also to consider whether the tire pressure is not normal to cause abnormal wear and tear, under normal circumstances, the tire pressure will exacerbate the tread center of the wear and tear, and tire pressure will increase the tread On both sides of the wear and tear; if the side of the partial wear, there may be deviation from the camber; due to the front beam caused by abnormal wear will be mentioned below)

4, axle and suspension parts were removed

Why should the four-wheel positioning adjustment, I believe you will be able to say a reason to come, the vehicle running in the deviation, we all know to do four rounds of positioning, because it affects your driving experience. Do not look on behalf of no problem? Regardless of the answer is yes or no, some of the number of one-sided, the chassis of the data quietly changed, it will change the driving characteristics, but the deviation is a phenomenon, this phenomenon can be perceived by most people.

For those recessive changes you need to have a more delicate mind to be aware of, but it seems that most people do not have such a capacity, the tire wear situation can be more real response to some minor changes, for example, a single tire Uneven wear and tear on the inside and outside may be due to abnormal changes in the eccentricity (of course, the daily driving habits have to be considered), and if the tread appeared a regular ups and downs (jagged wear), this situation Most of them will be accompanied by abnormal birth noise, you can be identified as the front beam appeared more serious deviation, need to repair the tire shop as soon as possible, as to whether the tire needs to be replaced, it depends on the wear and tear, if the tire wear Too serious, the four rounds of positioning made by the data will be inaccurate, in the rear positioning before the tire inspection part we will say.

As a normal loss of parts, the suspension part of the repair is inevitable, the aging of the buffer sleeve produced by the abnormal sound is more common in the replacement of related parts, in principle, is also need to do four rounds of positioning, this argument may Causing the opposition from the P Plus sound, indeed, this does not meet the majority of people's ideas, almost no one because of the suspension parts to clamor to do four rounds of positioning, this approach will not be understood, why I changed A control arm need to do positioning? The reason is that when we disassemble the suspension, the relative installation position will change, that is, this can not be estimated installation error, it may lead to abnormal positioning data, so in order to kill everything, in principle, need to do Positioning. However, in the installation process, the maintenance technician will basically fasten the screws in the original mark (the screw is removed when the mark will be left), to minimize the disassembly caused by changes in positioning data.

It is worth mentioning that the new car is not suitable for four rounds of positioning, because the chassis has a settlement process, as if the engine needs to run the same, the chassis "run-in period" is about 2000 km.

Four rounds before the inspection

1, tires (pattern depth and tire pressure)

The four-wheel positioning data is built on a relatively standard condition, so the calibration should be followed when calibrating the four-wheel position. In order to ensure that the front and rear axles are on the same horizontal plane, the dimensions of the four wheels should be the same in the tire side. In addition, minor differences should be taken into account, such as tire pressure, in accordance with the standard tire pressure adjustment in place Pressure level see the inside of the fuel tank cover); there are more subtle checks, tread pattern depth need to be measured, coaxial tires on the maximum depth of the deviation can not exceed 2mm, if not meet the conditions, depending on the situation to replace the relevant tires.

A new generation of four-wheel positioning system will be smarter, maintenance technicians through the measurement of these data into the system, it can be calculated according to the corresponding value to compensate for these external causes of the error.

2, hanging (visual suspension state)

The good condition of the wheel does not mean the beginning of a perfect four-wheel alignment adjustment, and you have to make sure that the chassis is also in a healthy state, which is more about the accident car, and sometimes the vehicle after the crash Will inevitably be a certain degree of damage, or even deformation, break the situation, the replacement of the chassis components will not have too many problems, but those who do not see any clues on the surface of the most likely to lead to four wheel positioning deviation, so , Led me to complete this task Chen master always "can see is not a problem," this sentence hanging in the mouth.

3, no-load conditions need to meet the conditions (to maintain the required no-load state)

This is the most easily overlooked link, where to do the same, it seems that no one concerned about it. The vehicle parked on the lifter should be in no-load condition, spare tire and vehicle tools to be placed in their respective locations, which is easy to understand and easy to do. The harsh requirement is that the oil storage tank and the amount of liquid in the glass kettle is also advertised up, need to reach more than 90%, you have to ask why? I can only tell you the manufacturers are also set in this condition, but you have to ask me why you buy a car when the fuel tank is always empty, is it done after the adjustment was drawn out? I really can not answer, perhaps this for a new generation of four-wheel positioning system can also complete the value of compensation it

Parking of the vehicle

Can do a four-wheel positioning is really not easy. It is not easy for me to open the elevator and place it in the appropriate position. First, not only the body is going, but also the front and rear wheels are in the center of the electronic corner plate and the rear slide.

Fixture and sensor installation

The fixture is equivalent to the sensor is fixed on the wheel of the conversion interface for the wheel with the fixed, in order to cope with the size of different rims, fixture fixed arm can be adjusted accordingly. The jaws have three fixed arms, each with a jaw at the end of the jaw to cling to the rim of the rim to ensure that the 3 o'clock is a plane, but in the course of the actual operation I find that there is always a claw that can not be adjusted Like the other two as honestly attached to the edge of the rim, which can not become a plane. (Please remember this picture, it is very important, in the back we will mention how to solve this error)

Four sensors are fixed on the wheel, through which to measure the location and angle of the wheel, and through the cable to the computer for analysis. It's the excitement of it, but the instrument is, after all, the instrument, it needs to let me tell it which wheel to monitor.

The choice of model information

Not only that, I also in the system to find the appropriate models to retrieve the relevant data information, which is as a measure of the car chassis data is correct if no basis, so the choice of models can not be wrong. This is done in the auto parts city to pay attention to positioning, in order to deal with the door of the business, their system stored in a large number of different brands of different models of chassis information, find the corresponding models of the year, to do the results only paste.

The most easily overlooked "offset compensation"

Do you remember that scene? I have three questions to determine a plane issued, the following will be resolved, the system called the program "offset compensation." So far, this is the time to a big move, but also let me see how powerful this lift device.

From the computer screen display, intuition told me that the red petal-shaped four wheels on behalf of the unqualified, when I still on the still picture of the analysis, Chen master has been located in the central slide at the elevator Jack (second lift) pushed to the back of the bridge near the pulley and the friction between the slide issued a dull and oily sound, sounds quite comfortable. With our common jack working principle is different from the jack power source from the compressed air, do not look down on the air of this medium, 2,3 tons of weight in front of it like a feather.

The rear of the body to lift until the rear wheel lifted off the ground, according to the instructions on the computer screen in front of the direction of rotation of the wheel, the original red will change from the angle to green, because each rotation will bring the sensor vibration , Resulting in its deviation from the horizontal position, so each petal from red to green after the sensor should be locked, sounds very complicated, the implementation of the operation is only a button to press it, until all the green after the description of the wheel Offset compensation has been completed, can be the next wheel correction work. The same way to lift the front of the car to the front wheel to leave the ground, by rotating the wheel to make up for the calculation error caused by the fixture. As the detection vehicle is a front drive, in order to avoid the rotation of the side of the wheel when the other side of the wheel due to the role of the sensor with a sensor rotation caused by changes in data and equipment and body damage, so the sensor in advance The locking pin is released. After adjustment, the results of the offset compensation will be displayed on the computer screen.

Offset compensation is a four-wheel positioning of a necessary project, it directly affects the final measurement accuracy, so must not jump.

After the adjustment will be the second lift down, lift also down to low, in order to restore the suspension to the normal position, need to press the body before and after the location. In addition, in order to carry out the work correctly and safely, it is necessary to tighten the handbrake and install the brake lock.

Pre-adjustment test

After so long, carried out so much work, the following adjustment before the test, really should be "three points to prepare seven points," this sentence, in essence, or ready to work, or to more accurate to the wheel State to determine.

After a variety of rounds, things are not finished, after showing the equivalent of a separate pre-beam value to determine the steering wheel in the middle position, after the need to do or hit the wheel, this time, that a little nervousness (the total failure of the sensor , And instantly return to normal) detection system to determine the steering center and the maximum total angle. The difference is that the sensor will interfere with the vehicle body when there is a large deflection in the wheel, so remove the two sensors from the front wheel and give the signal to the lower corner plate, between the sensor and the corner plate There is a data line connection, the data through the sensor and the system between the lines to pass. The cumbersome program not only does not make the wheel more difficult, but rather a lot of simple, because I just want to send the direction to both sides and stay for a moment, the system can be identified. But then the steering wheel is still tangled, after the completion of the last step to play the direction, the need for fixed steering wheel.