A system for converting a snowmobile into a wheeled vehicle is disclosed, and comprises a pair of wheel mounting assemblies for each being mounted on one of the front skid support assemblies of the snowmobile, and a swing arm for mounting on the snowmobile in a manner such that the swing arm is pivotable with respect to the frame. The swing arm has a forward end and a rearward end, and is mountable on the drive shaft such that the swing arm is pivotable with respect to the drive shaft. An axle is mounted on the swing arm toward the rearward end thereof, and a suspension mounting assembly is provided for mounting on the frame of the snowmobile and controlling pivot movement of the swing arm.