About terms
1. Four factors of wheel alignment are adjusted. All angles are given in degrees. Pivot point is an imaginary line drawn through the axle of the suspension strut and extended to the contact point with the road.
2. Camber angle is the angle at which the wheel plane is tilted from the vertical when viewed from the front of the vehicle. Positive camber is the angle (in degrees), by which the plane of the wheel is tilted outward from the top of the vertical, negative camber - angle (in degrees), which the plane of the wheel is tilted inward from the top of the vertical. The camber angle of each front wheel is not adjustable, however, both front wheels can be balanced by moving the suspension subframe. The camber angle of the rear wheels is also not adjustable and is provided for reference only.
3. Caster angle - the angle between the steering axis and the vertical when looking at the wheel from the side. Positive caster angle - the angle when the steering axis is tilted back from the top of the vertical. The angle is not adjusted in operation. As with camber, the data is provided for reference.
4. Toe-in is the difference between the front and rear distances between the wheel rims at the hub height. If the front distance is less, the toe-in is positive; if greater - negative. Convergence in angular degrees is determined by taking the central axial line of the car as zero.
5. The toe-in is adjusted by turning the steering tips in or out, changing the overall length of the steering rods. The toe-in angles of the rear wheels can only be balanced by moving the rear beam.
Checking and adjusting
6. Due to the need to use precise measuring instruments, it is better to entrust the adjustment of the camber and toe to specialists in a suitably equipped workshop. The longitudinal tilt angle of the steering axis is set during the manufacture of the car, its deviation from the norm can occur only after an accident or serious wear of the suspension supports.
Front wheel alignment adjustment
7. There are two methods of checking. The first method is to use a measuring ruler to measure the distances between the wheel rims. Other methods are more accurate, but require expensive equipment, the purchase of which for one-time purposes does not seem reasonable. Such equipment is usually available in specialized workshops.
8. To ensure accurate measurements, unload the vehicle, fill the tank with fuel, place the spare tire and on-board tool kit in the trunk. Inflate the tires as described in Weekly checks. Pump the car several times to get the suspension into working position, set the wheels to the straight-ahead position.
9 The necessary adjustment is made as follows: Apply the handbrake, then raise the front of the car and install safety supports.
10. First clean the threaded parts of the tips. Before unscrewing, moisten corroded tips with a penetrating liquid (like "Liquid Wrench").
11. While holding the adjuster still, loosen the locknuts of the tip and rod. Adjust the length of the rod by turning the adjuster; reducing the length of the rod increases the toe-in - and vice versa.
12. After completing the adjustment, hold the adjuster and tighten both lock nuts to the specified torque.
13. If after adjustment the steering wheel spokes are not horizontal when the front wheels are set to the straight ahead position, remove the steering wheel and reposition it as described in paragraph 14.
14. Lower the vehicle and check the wheel alignment, adjust if necessary.
This article was copied from the website AudiManual.ru