Before measuring the wheel angles, a play detector is used to ensure that all bushings and bearings are free from excess play. This is necessary in order to determine wear and tear on wheel suspension and steering systems.
The ideal feature with the JOSAM play detectors is that they can be mounted easily in the workshop without any concrete casting. Three expander bolts are used on each side and the pump is fastened in the pit wall or the workshop wall.
The checkup itself is carried out by driving the axles, pair by pair, over the plates. When the axle is placed onto the plates the brake is applied. The play is analysed on the opposite side of the plate which has been set in motion, i.e. if you shake the left side the play is checked on the right side. The operator steers the movement of the plates by means of a control handle that has a built-in light as well.