Wheel Alignment: Inspection: Caster

Place the front wheel on the turning radius gauge. Make sure the ground contact surfaces of front and rear wheels are at the same height.
Set the adapter at the center of wheel, and then attach the wheel alignment gauge.

Fig 1: Identifying Alignment Gauge, Turning Radious Gauge And Adapter
Courtesy of SUBARU OF AMERICA, INC.
Measure the caster angle in accordance with the operation manual for wheel alignment gauge.
CASTER SPECIFICATION CHART

Caster

4°04' (Reference)