I was one of the suckers that replaced the 380 with the 3900. The first year I had it in the shop 5 times for warranty service. Received the chain guard to install when the whole drive train system fell apart. I ordered and received the upgrade/tune up kit which by all accounts may be the answer to most of the problems we have. My question is regarding the wheels. The tune up kit only comes with one wheel for the single wheel side. The side with two wheels only has the axles. The two wheels from my unit have the chain sprockets/gears attached and will not attach to the new unit. Am I missing something? How do you attach the wheels?