FCAR FD505 Wheel Alignment System User Manual
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Thrust angle causes the tail of the vehicle to be biased to one side. In order to make
the vehicle go straight, the front wheel has to turn to the direction of the thrust line.
Therefore, if the toe angle of the front wheel is not compensated for the thrust angle, the
steering wheel must turn to one side when the vehicle goes straight. If the toe angle of the
rear wheel can be adjusted, the thrust angle should be adjusted as close as possible to zero.
The Thrust line direction is the actual running direction of the vehicle and is
determined by the toe angle of the rear wheels. When the direction of the thrust line does
not coincide with the geometric centerline of the vehicle, in order to go straight, the
steering wheel must be turned to an angle, resulting in an imbalance of the steering wheel.
At the same time, the driving route of the rear wheel does not coincide with the driving
route of the front wheel. This phenomenon is called "rear wheel traverse". When the thrust
line is not directly in front, the steering wheel must be turned to one side to ensure the
straight line of the vehicle, which causes the steering wheel to be unbalanced.
If the thrust line is neglected, the accuracy of the positioning cannot be guaranteed,
which is the main reason for the full deviation of the steering wheel.
Selecting the thrust line as a measurement can do the following:
☆
After adjusting the toe angle of the rear wheel to the specified value (factory
specification value), the thrust line and the vehicle center line coincide. For vehicles with
adjustable rear suspension, the toe angle of the rear wheel should be adjusted so that the
thrust angle is as close as possible to zero.
☆
The steering wheel can be adjusted to balance by the thrust line reference,
regardless of whether the thrust angle is zero or not.
When the rear wheel toe is not adjustable, the front and rear wheel toe angles can be
adjusted to be the same by adjusting the front toe angle, and they are set to the angle at
