Go over the entire loco and tighten/check ALL accessible screws, especially coupler mounts. Both of my spectrums were notoriously bad for loose screws. I still have to get a part of the front coupler assembly on the 2-truck shay from Bachmann -found part of it on the track but not the machine screw and retainer plate that holds it all together. /DesktopModules/NTForums/themes/mls/emoticons/sad.gif