When I got my first snow cat I didn't know anyone else that had one. Since you can't call 'Triple A' from the top of Mt. Ranieer and they don't offer service to snow cats in distress, I carried practally an entire machine in spare parts. As it turned out the number one item was a shovel. This is far more important than a winch if you get stuck. You can always dig yourself out but there isn't always something to hook the winch to. Spare Gas is a good Idea too. I also brought multiple flashlights, coleman stove, coffee, tea, extra gloves, spare hardware for the track, a couple grousers and guides, a fuel pump. With OLD snow Cats fuel system problems tended to be the most common single failure. A Boat gas can with the hose, quick disconnect and primer pump (Bulb type), was a life saver. I also always carried a pair of snow shoes and a pair of skiis. When the machine got stuck or broke down I Skiied down to the truck and got the "Spare" snow cat. The Cascades are steep enough that it generally only took half an hour to Ski down to the Truck when it had taken 3 hours to get up to the point where it broke down or de-tracked. Eventually we started taking 2 machines, but we still hauled a bunch of spare stuff and often resorted to using it. Oh yes, a good jack or even multiple jacks, wood blocks and some pieces of plywood. A jack tends to sink right into the snow so a 2' by 2' piece of 3/4 plywood makes a good work platform. Wire seems to be handy, and Duct Tape!