Check out for the best clamp solution. Also see Snowest post Happy-Face Pro Collar - Available Now - SnoWest Snowmobile Forum
Pro Clamp - Time For a Beer - SnoWest Snowmobile Forum Cheep insurance to make sure you get in and out everytime.
If you do not want to take the chance of waiting for the clamp from Polaris these guys have a nice fix for cheep insurance. When the shaft breaks to will destroy the tunnel also in most cases.