If you notice that the car is pulling to the side for no apparent reason, or the tires on the front wheels are wearing unevenly, it’s time to check your wheel alignment. Modern motorists are accustomed to having everything done at a car service center. Fortunately, every 500 meters you can see signs: “3D collapse”.
Is an expensive service really necessary, or can I do this procedure myself?
- A stand for checking and setting wheel angles certainly simplifies the process itself. The car stands strictly horizontally, the front wheels are located on rotating disks. In addition, thanks to the laser measurement system, the accuracy is quite high. There is no need to delve into angle tables and try them on your car, the information is in the databases. This is the positive side.
- On the other hand, despite all this electronics and “laser guidance systems,” the nuts are turned by an ordinary mechanic. Often of dubious qualifications. So the error is determined not by the cost of the equipment, but by the straightness (or crookedness) of the car mechanic’s hands.
All this equipment is designed to speed up the process and its commercialization.If setting wheel alignment angles on a bench takes no more than 30 minutes, then in a garage you can spend several hours. And if you don’t have a pit, the process takes even longer.
As for the accuracy of measurements, the walls of houses, built according to the water level and plumb line, are no more crooked than modern buildings that were measured with a laser level.
Our fathers and grandfathers had not heard anything about the sophisticated stands; the queue at the car service center was no less than at Lenin’s mausoleum. Nevertheless, the cars drove smoothly, and the tires wore out evenly (taking into account the shortage - the tires were cherished like the apple of their eye).
How was this done?
In the “Maintenance Instructions” of the car, among other parameters, there are camber, toe and caster angles. Don't you have such a book? Everything is correct! Car dealers believe that the owner only has the right to turn the steering wheel and change gears. The rest should be done by an authorized service, and at your expense. Therefore, only the “Operating Instructions” are included with the new car. Which details how to change radio channels on your multimedia system and turn on heated seats.
If you try, you can find information for any make of car. First, let's define the terminology:
- Camber is the angle of deviation of the wheel plane relative to the vertical. That is, the wheels stand either “house” or “boat”.
- Toe is the angle of deviation of the wheel plane relative to the longitudinal axis of the car. The wheels can be aligned strictly along the axle, or the distance between the front edges is less than between the rear ones. The wheels seem to point to one point on the horizon.
- Castor is the angle of deviation of the rotation axis from the vertical. The axle is usually tilted backwards.This parameter cannot be set at home.
Camber installation
Having obtained these indicators (in degrees), we convert them to millimeters. To do this, draw an imaginary triangle (see illustration).
The camber angle is known, as is the disc diameter. We calculate the camber deviation in mm using a school geometry course. The resulting value is the difference in the distance between the lower and upper edges of the disk relative to the vertical. It’s easy to install the vertical: hang a plumb line on the wing.
And we measure the deviation. Adjustments are performed differently on each vehicle. As a rule, the axles of the suspension arm are secured with bolts - eccentrics. But this is a matter of technique: the main thing is to understand the principle.
Convergence
Here the procedure is much more complicated. First, prepare the surface under the front wheels. They should turn relatively easily. There are no rotating supports in the garage, so we smear the floors (you can put pieces of old linoleum) with a soap solution.
And we run our front wheels onto a slippery area. Then you need to fix the steering wheel in the “straight” position. This can be done using a long board and a level.
We stretch the fishing line along the centers of the hubs. It should be the same distance from the centers of the front and rear wheels.
We calculate the difference in the distance from the line to the leading or trailing edge of the disk in the same way as for camber. Of course, not in degrees, but in millimeters. Carefully rotate the toe-in adjustment clutch (in different car models, the design may differ).
And we achieve the correct installation angle. The procedure must be repeated several times, checking the distances on both edges. When you turn the wheel, both distances change.
Similarly, we set the toe of the second wheel.
The accuracy of setting the angles depends only on your accuracy and patience.After finishing the work, your humble servant stopped by a friend’s for a service (where there is a 3D stand). We tested the angles - everything turned out to be within factory tolerances.
Conclusion:
If you have the space and time to service your car yourself, you can save money on basic operations.
