What is wheel alignment and why should this be monitored

If you are faced with the fact that with the steering wheel lowered, the car leads away, then in most cases it is necessary to adjust the alignment. This is an important parameter that determines the safety and comfort of a vehicle. But in addition to the collapse, there is a third important parameter, but more on that later. 

What is wheel alignment?

This parameter indicates the angles of the wheels in relation to each other, as well as to the wheels to the plane of the roadway. 

Car manufacturers, for each model provides individual parameters for the angles of the wheels, at which the efficiency of the suspension and steering will be maximum. 

The camber angles have different meanings even on one car, depending on the configuration. When the vehicle is standing or moving without load on a flat road, then the wheels should stand flat relative to the road. When loaded, the collapse goes in the negative direction, so old cars did with a positive collapse. More modern cars have a negative camber, because such angles provide the best stability. 

Nothing has changed with the convergence: when moving, the front wheels tend to “go out”, so initially the front wheels look inward. 

Why it is necessary to regulate alignment

When a wheel hits a large pit or after even a small accident, some of the suspension and chassis elements of the car are displaced. Of course, the displacement coefficient directly depends on the force of the impact.

Camber must be done even if the driver drives carefully and has never had an accident. If you do not make these adjustments, the vehicle will become unstable. And this is just the tip of the iceberg.

The fact is that the loss of stability of the machine increases the risk of an emergency. Also, an incorrectly exposed (or offset) wheel alignment on straight sections of the road will lead the car to the side. To maintain the position of the vehicle in the lane, the driver will turn the steering wheel in the desired direction. The result is uneven and severe tire wear.

In some cases, the car behaves extremely unstable on the road - it wags on the sides, and you have to constantly "catch" it. Even in this case, you can forget about the long-term resource of the rubber of the wheels, because the wheels do not have the proper contact with the asphalt. There are cases when 20 thousand kilometers did not pass between the replacement of new tires.

Wheel angles directly affect ride comfort and safety. If the parameters are far different from the factory ones, the suspension will live its own life and react incorrectly to driver control. Problems that arise with knocked down corners:

• the car goes off track, goes to the side, constant steering is required, which often leads to an accident;
• at high speed, the car throws;
• increased wear on tires and suspension parts;
• fuel consumption increases by 5-10%.

When to do alignments

Wheel alignment should be done in the following cases:

• the car moves away in one direction or “throws” around;
• uneven tire wear;
• after repair of the suspension and steering (replacing ball joints, dismantling and mounting levers, replacing rods and steering tips and shock absorbers);
• in case of inadequate behavior of the car on the road (with an independent rear suspension, the car, with rectilinear movement, can “throw up” on the sides).

Leads to the side: you must make sure that the suspension parts are working, which affect the angles of the wheels (traction and steering tips, silent blocks, ball bearings, wheel bearings). 

Uneven tire wear: running gear diagnostics should also be carried out; if there was a strong impact of the wheel, then check the lever for geometry. 

Suspension Repair: in this case, after repairing the suspension, the wheel alignment is broken, as well as the caster (when replacing shock absorbers). Before visiting the “collapse”, a long ride of more than 50 km / h is not recommended in order to avoid strong and uneven wear of the rubber.

Wheel alignment

Toe-in is called the angle with respect to each other. If you look at the wheel from above, then the distance between the front of them will be less. When moving, the law of the force of resistance operates, creating a turning moment about the axis. In simple words - the wheels will tend to outward, and when reversing - vice versa. This applies to rear wheel drive vehicles. This parameter is called positive convergence. 

For front-wheel drive cars, where the wheels are simultaneously turned and steered, the wheels will tend to the opposite - inward, this is called negative convergence. 

By the way, in the rear independent suspension, toe-in traction is actively used, which can be adjusted. Due to this, the rear of the car is able to steer, helping to turn in the correct trajectory. 

How to set the right angles of the convergence of the wheels:

Before adjusting the toe-in, the steering hinges must be checked, steering nut nuts developed, the degree of tightening of the lever to the steering knuckle. All passenger cars and commercial vehicles weighing up to 3500 kg can be adjusted for convergence at the stand using a computer. Nowadays, the most common equipment is 3D camber, which help to set angles to the nearest degree. 

The car is mounted on a stand, special targets are connected to the wheels, which are calibrated by moving the wheels back and forth and to the side. Information on wheel angles is displayed on the computer monitor, first you need to select the make, model and year of manufacture of the vehicle in order to set the factory parameters.

The razvalchik begins to adjust the steering tips, tightening the nut in one direction or another, depending on the position of the wheel. When on the monitor the angle of convergence shows on a green background - the tip is clamped, this side is exposed. The same operation takes place on the other side. 

Camber

Camber is the angle between the wheel axle and the vertical. The collapse is of three types:

• zero - the upper and lower axles of the wheel are the same;
• negative - the upper part is littered inward;
• positive - the upper part protrudes outward.

Zero camber angle is achieved when the vehicle is moving, provides stability and uniform fit of the tire to the road surface. Negative camber increases in proportion to the mass of the car, it has better stability, but tire wear increases in the inside. A positive angle is found on old cars and tractors, compensating for the softness of the suspension and the weight of the car.

The rear suspension is also adjustable, even semi-dependent. For example, for VAZ front-wheel drive vehicles, negative camber plates are provided that are installed between the beam and the hub. Plastic shifts the top axle of the wheel inward, increasing cornering stability and high speed. On independent suspensions, breakup levers are provided, which also need to be adjusted. Their presence significantly increases comfort and traffic safety.

How to set the camber angles:

Adjustment is also made at the stand. Depending on the design of the suspension, the camber is regulated in different ways, namely:

• double-lever suspension (VAZ 2101-2123, Moskvich 412, GAZ 31105) - adjustment is made by placing washers of different thicknesses under the axis of the upper or lower arm. It is required to unscrew the two bolts of the lever axle, and insert washers between the beam and the axle, controlling the camber angle;
• double-lever suspension of modern cars - eccentric bolts are provided, which, rotating, take the lever out or in. The bolt is marked with risks indicating the degree of adjustment;
• independent rear suspension has at least one lever per side, which adjusts these angles. As a rule, the lever consists of two parts interconnected by a threaded axis, due to which the lever is lengthened or shortened;
• MacPherson strut front suspension - adjustment by the position of the shock absorber. The shock absorber strut is attached to the steering knuckle with two bolts. The holes in the rack are oval, due to which, when the bolt is loosened, the shock absorber can be extended or retracted. 

Camber adjustment is done along with the convergence. Before this, you need to make sure the integrity of the suspension parts. The real angle of all 4 wheels is indicated on the computer monitor. As indicated above, for each type of chassis, the adjustment is made in different ways: by inserting or removing washers, adjusting the suspension strut, rotating the eccentric bolts or adjusting the length of the lever. 

How long does the wheel alignment take? On average, it takes 30-40 minutes, provided that all bolts and connections are designed.

The angle of the caster. This parameter is responsible for the stable rectilinear movement of the wheel. To understand the angle of the caster, it is worth taking a look at the location of the front wheel relative to the arch: if it is shifted backwards, this affects the control characteristics, and the angle of the caster must be the same on one axis. With a properly tuned caster, releasing the steering wheel, the car moves straight. Most often, the angle of the caster is set by the manufacturer and cannot be adjusted. If the parameters deviate, diagnostics of depreciation struts and front suspension arms is required.

How to choose a service station

Many service stations can assure that they provide high-quality wheel alignment. However, if the master immediately puts the newly fitted car on the stand and starts tuning, you can freely interrupt the procedure and look for another service station.

The fact is that the correct angle of inclination of the wheels cannot be established with a faulty suspension of the machine. For this reason, a professional will first make sure that this system is in good working order. As a result of diagnostics, hidden problems are often revealed that subsequently affect the position of the wheels.

Only after the master has diagnosed the suspension and chassis, he begins to adjust the camber. Serviceable parts have minimal backlash (and in some, it should be absent altogether). Otherwise, the angle of the wheels will be set incorrectly (if at all on the faulty chassis the master will be able to do this).

For these reasons, before letting the specialists start setting up the machine, it should be clarified whether they are doing a running gear diagnosis or not.

And one more nuance. If the driver drove a car with a downed camber for a long time, then the tires on it have already worn out. It so happens that after a high-quality setting, the car still behaves unstable. In this case, you should pay attention to the quality of the rubber, and ideally replace it with a new one.

For information on how you can make wheel alignment at home, see the following video:

Camber - Convergence. Do-it-yourself grandfather's way. Descent Collapse without service station

Questions and answers:

How to check the camber toe? On a level surface, the wheels are installed straight. Marks are applied to the top and bottom of the tire. Using a plumb line lowered from the wing, the distance to the marks is measured. The wheels are rotated 90 degrees and the measurement is repeated.

What is wheel alignment needed for? If the camber is correctly adjusted, the car will be more controllable, which has a positive effect on safety and also on the tire change interval.

What happens if the wrong wheel alignment? The car will lose proper handling at high speeds, fuel consumption will increase, and tires will wear unevenly.