Collapse – is the tilt of the wheel in the vertical plane relative to the center line of the car. It can be positive if the wheels are tilted outward or negative if the wheels are tilted inward. The camber angle mainly affects the uniformity of wear of the front tires. If the camber of one wheel is positive and the other is negative, the car will pull to the side when driving straight.
Convergence – the difference in distance between the front and rear edges of the wheels. Positive toe-in means that the front wheels are closer together than the rear wheels when measured at the height of the midpoint of the wheel. Negative toe-in means that the front wheels are further apart than the rear wheels.
Lateral tilt of the wheel pivot axis – this is the angle between the axis of inclination of the steering knuckle and the vertical drawn through the wheel attachment point, looking in the longitudinal direction of the car.
Due to the camber angles and the transverse tilt of the steering axis, the points of contact of the wheels with the road are located closer to the axis of the steering knuckle. This supports the so-called "rolling shoulder", the easier it is to control the car. Also, impacts from uneven surfaces are less transmitted to the steering.
The longitudinal tilt angle of the pivot axis. The axis around which the wheel turns is placed in space so that its lower part is directed forward. Such an angle of longitudinal inclination is called positive. With a positive angle, the self-return of the wheel to the middle position after turning is improved.
Adjusting the toe-in
1. Set the front wheels straight. There are markings on the steering shaft and steering gear housing. Set the steering so that these markings match.
2. Loosen the clamp nut on each steering rod (arrow on the illustration). Adjust the toe-in by rotating the left and right steering rods. In doing so, turn the left and right steering rods by the hexagon by the same amount. Make sure that the ball joints and boots do not twist when adjusting.
3. After completing the toe-in adjustment, tighten the clamp bolts on the steering rods to a torque of 80 N·m.
[The original article is available on the website BMWMAN]