Measurement of wheel alignment angles is impossible without special measuring instruments. Therefore, we confine ourselves here to a description of the basic concepts necessary for measurement.
Toe-in / camber / lateral inclination of the axis of rotation of the wheel / longitudinal inclination of the axis of rotation of the wheel (run-out)
Under convergence refers to the lateral distance between the wheels. The front wheels, as a rule, should have a positive convergence, since the wheels scatter slightly outward due to camber and rolling resistance, since there is play in the hub bearings, wheel suspension and tie rod ends. Positive convergence means it compensates for the tendency of the front wheels to scatter outward. With positive toe-in, the wheels are set so that, measured at midpoint height, the front wheels are closer together than the rear.
Camber and lateral tilt of the wheel axis reduce the transfer of shocks from the road to the steering and maintain the least friction when cornering.
Camber is the angle at which the wheel surface deviates from vertical control. The front wheels are thus tilted, with negative camber, for example, the wheels at the attachment points are further apart than at the top. Lateral inclination of an axis of turn of a wheel is the beta angle between the axis of inclination of the steering knuckle and the vertical drawn through the wheel attachment point, looking in the longitudinal direction.
Due to the camber angles and the transverse inclination of the axis of rotation, the points of contact of the wheels with the road are located closer to the axis of the steering knuckle. This maintains the smallest so-called running-in shoulder. The smaller the break-in shoulder, the easier the control. Also, bumps from the road have a weaker effect on steering. Longitudinal incline axis of rotation wheels (run-out) is the angle between the axis of the steering knuckle and the vertical at the wheel attachment point, looking across the vehicle. The coast has a significant effect on the movement of the wheels in a straight line. Too little overrun causes a deviation from the desired direction when driving on bad streets or with crosswinds and does not allow the steering to return to its original position after cornering. On the other hand, a large overrun increases the control force.
Runout, camber and lateral inclination of the axis of rotation of the wheel on the MAZDA 323 can only be checked, they are not subject to adjustment. If the measured values are outside the tolerance range, the suspension parts are damaged or worn.
Adjustment
To check the angles of the wheels, a viewing hole or a lift with a platform is required. The following conditions must be met for each measurement.
- Prescribed tire pressure
- The vehicle is unloaded and fully loaded.
- Car pre-rock strongly
- Steering wheel in middle position.
- Absence of unacceptable backlash in the steering rods (maximum steering wheel play at the outer edge 30 mm)
- No unacceptable play in the wheel suspension
- The vertical and lateral runout of the wheel disks should not exceed 2.0 mm.
- The difference in height between the left and right sides of the vehicle, measured at the edge of the fender, must not exceed 10 mm.