I've got a Z422 with 9 hours that has a siezed caster wheel bearing on one side and the other side is not far behind. Neither bearing appears to have any grease in it. I dont want to make the 2 hour round trip to fight with the dealer about warranty. Does anyone know the bearing part number? Couldnt find it in the manual. One wheel is also leaking air around the bead. Anyone seen this problem before? Thinking about popping the bead and seeing if that will work.