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Chapter III Operation
Toe Curve Change
This feature allows measurement of individual wheel
toe change as the suspension system goes through
jounce and rebound (spring compression and expan-
sion). An excessive amount of toe change can cause
premature tire wear. A large change on only one side
can cause “bump steer”, a dangerous condition causing
the vehicle to rapidly change directions when bumps
are encountered. While there are no specifications for
the amount of change, it should be fairly small, and a
comparison of left and right wheels can assist in diag-
nosing defective steering system components.
Follow the on-screen instructions carefully to move the
suspension through a 60mm (2.3”) travel. This can be
done by pulling down or pushing up the suspension.
Use a ruler or tape measure to observe the proper
amount of frame movement. Select OK when com-
pleted to display the results.
TIP: On cars with rack and pinion steering, a bump
steer condition is usually created by worn rack mount-
ing bushings that allow the entire rack to shift when
bumps are hit.
Camber at Zero Toe
This routine measures camber on the left and right front
wheels individually at zero toe. This is the recommended
procedure for vehicles with high caster specifications,
such as Mercedes-Benz.
The procedure is as follows:
1. Select Camber at Zero Toe from Measure
Screen.
2. Using the on-screen meter, turn the left wheel
towards the center until the meter turns green.
3. Press OK to continue.
4. Repeat this process for the right wheel. Click
OK to continue.
5. The results are displayed above the wheel
graphics. Click “Next” to return to the readings
screen.
Summary of Contents for Pro42
Page 1: ...Operators Manual Portable Imaging Alignment Systems with Pro42 ...
Page 2: ...Blank page ...
Page 8: ...Page 8 Table of Contents ...
Page 65: ...NOTES ...