Wheel alignment angles (Opel Vectra A)

Optimum driving characteristics and minimal tire wear are only achieved with the correct front wheel alignment. If tire wear is abnormal, the vehicle does not maintain its direction of travel well, or if cornering is poor, you should contact a workshop to have the appropriate checks performed.

An accurate check of the wheel alignment angles can only be carried out on a suitable measuring stand. Therefore, this chapter describes only the basic concepts and the procedure for adjusting the wheel alignment.

Basic concepts

Wheel alignment

Toe-in is the difference in the distances between the side surfaces of the front wheels at the front and rear. The front wheels must have toe-in because the deflection and rolling resistance when driving forward due to play in the wheel bearings, suspension and steering rod joints cause the wheels to deviate slightly outward. Toe-in compensates for this deviation. To set the toe-in, the front wheels are adjusted so that the distance measured between the wheels at the middle of their height is less at the front than at the rear, i.e. the wheels are slightly closer together at the front.

Wheel alignment and lateral tilt

Camber and caster reduce the impact of road surface irregularities on the steering wheel and provide minimal tire friction when driving around curves.

Camber is the angle at which the plane of the wheel deviates from the vertical. Thus, the front wheels are installed at an angle and are closer to each other at the point of contact with the ground than at the top.



Caster angle is the angle between the steering knuckle axis and a vertical line drawn through the point where the tire touches the ground, looking in the direction of the longitudinal axis of the vehicle.

[Article published on the website OPELBOOK.ru]

Due to the camber angles and the inclination of the steering axis, the contact points of the wheels with the road are close to the rotation axis of the steering knuckles. Due to this, small values of the rolling shoulder are maintained. The smaller this value, the less force is required to turn the wheels. In addition, the steering is significantly less affected by impacts due to unevenness of the road.

In Opel Vectra/Calibra cars the rolling shoulder is negative. Thanks to this, maximum stability of the driving direction is maintained in case of uneven braking of the front wheels.

Longitudinal tilt of the steering knuckle axis

The longitudinal tilt of the steering knuckle axis has a significant effect on driving stability. Too little tilt causes the car to pull to one side on poor road surfaces and in crosswinds, and also makes it difficult to return the steering wheel to the straight-ahead position when exiting a turn. The tilt of the steering knuckle axis is determined by the design, by a certain angle of rotation, and is not adjustable. The value of this angle, however, should be checked after repairs to the front suspension or front axle beam (is done in the workshop).