I checked the wheels/axles last night and there was some cottony "snow" wound around the axles etc.. I took the wheel mechanisms/drive rods off and cleaned it all up. I didn't realize the smoke unit piston could possibly have become tangled up as well. That may be my culprit.
If that's the case, how do I take the shell off? I've taken every screw out of the bottom (and behind on the bumper) and the shell still doesn't come free. Am I missing something here?