BMW X5: Additional Work For Camber Correction

IMPORTANT: Changes in axle geometry caused by accidents must under no circumstances be rectified by camber adjustment!

NOTE: The upper control arm may only be replaced if the camber is outside the specified tolerance after toe adjustment.

Adjust toe-in.

Check camber values; if necessary, replace upper control arm with over-or under dimension variant.

NOTE: Control arms with + or - marking (see Fig. 7) are camber correction arms:

- Under dimension variant

+ Over dimension variant

These camber correction arms are used to correct the camber values by 30 minutes. To be used only if the tolerance values are exceeded or undershot!

Fig. 7: Identifying Under Dimension And Over Dimension Variant Marking On Control Arms

An unmarked control arm is a standard part.

After installation:

• Check directional stability of car; if necessary, repeat toe-in adjustment.

CHASSIS/WHEEL ALIGNMENT CHECK PROCEDURE

CHASSIS/WHEEL ALIGNMENT CHECK PROCEDURE STEPS

GENERAL CHASSIS AND SUSPENSION DEFINITIONS

Fig. 8: Identifying General Chassis And Suspension Definitions

1. Toe
2. Camber
3. Caster (with 10º or 20º wheel lock)
4. Toe angle difference (with 20º wheel lock)
5. Wheel offset
6. Camber
7. Rear-wheel position
8. Toe
9. Geometrical axis

GENERAL INFORMATION AND DEFINITIONS

Toe angle difference

a Toe angle difference

D Center point of operating circle

The toe angle difference is the angle adjustment of the inner cornering wheel relative to the outer cornering wheel when negotiating a curve. Steering is designed in such a way that angular position of wheels changes as steering lock progresses.

A correctly adjusted toe angle difference produces equal values for left and right lock with consideration of factory tolerances.

Toe angle difference provides information on corresponding operation of steering trapezoid for left or right steering lock from center position.

Fig. 9: Identifying Toe Angle Difference

Camber

Inclination of the wheel from the perpendicular.

Fig. 10: Identifying Camber Angle

Toe

Reduction in distance of front of front wheels to rear of front wheels. The toe-in prevents the wheels from moving apart during driving and thus:

• the wheels from vibrating and grinding
• excessive tire wear
• excessive strain on the steering linkage and its links/joints
• heavy vehicle steering

Measurement is performed in "straight-ahead mode".

Fig. 11: Identifying Toe Angle

Caster

Is the inclination of the kingpin in the direction of travel viewed from the side. The line through the center point of the spring strut support bearing and the control arm ball joint corresponds to the "kingpin".

Thanks to caster, wheels are pulled and not pushed. In a similar manner to king pin inclination, when driving in curves or around corners, returning forces are reproduced to help return wheels to straight-ahead position.

Fig. 12: Identifying Caster Angle

Geometrical axis 1

Is the angle bisector from the total rear-wheel toe.

Front-wheel measurements are taken in reference to this axis.

Symmetrical axis 2

Center line running through front and rear axles.

Fig. 13: Identifying Geometrical Axis 1

Wheel offset

Angle by which one front wheel is displaced more towards front or rear than the other front wheel. The wheel offset angle is positive when the right wheel is displaced towards the front and negative when it is displaced towards the rear.

Fig. 14: Identifying Wheel Offset

Kingpin offset/scrub radius

Is the distance from the center of the wheel contact face to the intersection point of the kingpin extension. The line through the center point of the spring strut support bearing and the control arm ball joint corresponds to the "kingpin".

The scrub radius is influenced by camber, kingpin angle and wheel offset of the wheel rim.

Fig. 15: Identifying Kingpin Offset/Scrub Radius

IDENTIFICATION OF SUSPENSION WITHOUT LABEL

NOTE: If the front spring strut does not have a label for suspension identification, the type of suspension can be identified from the part number in the Electronic Parts Catalogue.

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