BMW 5 Series E39

since 1996-2001 release

Repair and operation of the car

Check and adjustment of angles of installation of wheels

Achievement of optimum running parameters of the car and the minimum wear of tires perhaps only at the correct provision of wheels. At the increased and uneven wear of tires, and also the unstable movement the car at the direct provision of a steering wheel and bad controllability on turns it is necessary to make optical verification of the provision of wheels.

It is impossible to check the angles of installation of wheels without the corresponding optical devices. For this reason the description only of basic provisions on check of angles of installation of wheels is provided in the Management.

Values of the main angles of installation of wheels are given in Specifications.

Convergence, disorder, corner of a cross inclination of an axis of turn of a wheel, corner of a longitudinal inclination of an axis of turn of a wheel

The convergence of wheels represents a difference of the distances between wheels measured at height of their axes between edges of rims. If the distance ahead is less than behind, the negative convergence takes place if on the contrary, a positive convergence. The convergence can make 0 °5 '± 10’ (E39).
Disorder and corner of a cross inclination of an axis of turn of a wheel reduce transfer of pushes at the movement of the car by steering and at the same time reduce friction at the movement on turns.

Disorder represents a wheel plane deviation corner from a vertical. Forward wheels thus stand at an angle. At negative disorder, for example, distance between wheels in a point of their contact are expensive more, than in the top point.

The corner of a cross inclination of an axis of turn of a wheel represents a corner between the axis of turn of a wheel and a vertical which is carried out in a wheel contact point, looking at the car in the longitudinal direction.

Existence of corners of disorder and inclination of an axis of turn of a wheel brings closer a point of contact of a wheel with the road to an axis of turn of a wheel. Thanks to it the so-called radius of a roller of steering transfer decreases. The less the specified radius, the is easier driving on turn. Besides, dynamic impact on steering of the car significantly decreases.

The corner of a longitudinal inclination of an axis of turn of a wheel represents a corner between an axis of turn of a wheel and a vertical in a point of contact of a wheel, looking at the car sideways. The longitudinal tilt angle of an axis of turn of a wheel significantly influences straightforwardness of the movement of the car. Existence of a longitudinal tilt angle of an axis of turn of a wheel provides return of the operated wheels to provision of the rectilinear movement, in particular, at movement along bad roads and at impact of a side wind.

Conditions of check of angles of installation of wheels