A separate kit is also available for TerraStars with spring suspensions.
According to Onspot, the Automatic Tire Chain system provides the traction of a single set of conventional snow chains at the flip of a switch, without stopping the vehicle. An electric switch is mounted in the cab and connected to an air solenoid mounted on the vehicle’s frame rail. Compressed air to the solenoid is supplied from either the vehicle’s onboard air system or a 12-volt compressed air kit.
When the dashboard switch is activated, the solenoid opens allowing compressed air to enter the air chamber and lower the chainwheel so it contacts the inside of the tire, the company said. The resulting friction between the tire and the rubber-covered chainwheel causes the chainwheel to rotate, creating enough centrifugal force to flail the chains out in front of the tire.
Six lengths of chain spaced at 60-deg. intervals ensure that there are always two chains between the tire and road surface.