turning radius gauge is an instrument, consisting of a turntable
and an attached gauge, which measures how many degrees the front
wheel of a vehicle has turned left or right. Turning radius gauges
are often used, during wheel alignment, when measuring caster, camber,
and toe-out on turns.
Turning radius gauge turntables are placed under the front wheels. The upper plate
in the gauge rotates on the lower plate allowing the front wheels to be turned
during an alignment procedure. A degree scale and a pointer on the gauge show the
number of degrees the front wheels have turned. On a four-wheel steering vehicle,
turning radius gauges are also placed under the rear wheels.