I noticed one of my non-powered diesels would constantly derail in the same spot on our modular layout. But none of the other NP units would derail there, or anywhere else on the layout for that matter. When I got home, I carefully checked the engine for something obvious- nothing found. So I got out a section of straight track, verified it was flat with a straight edge, a put the engine on it. The rear truck sits correctly on the track, with all 4 flanged wheel treads touching the track. However, the front truck does not. Only 3 wheels touch the track-the fourth is a good 1/8" above the track. If I push down on the truck, it rocks. So, problem found! The questions are: What is wrong with it? Can I fix it myself, or, do I send it back to MTH?
Chris