Recently bought new Lionel Legacy Alco PA powered and unpowered units ... AF48025 - D&H LEGACY PA AA SET (17AF).
Ran it for the first time today and the front truck/wheels derailed on some curves. Upon investigating, I note interference between the side of front truck and the crew ladder on the inside side of my track layout curves. Same for both the powered and unpowered units since the ladder is located identically adjacent to the front trucks. My track is all original Gilbert R20 with rubber backing. I took some photos of the side of the truck/ladder interference on a curve ... side view and front view showing the interference. I also removed the truck and took a photo showing no interference. I also ran the engine around the track layout without the truck and ... no derailing on any curves. It is the truck/ladder interference that causes derailing.
Here's my question to other S-gaugers who may have had similar issues. My options appear to be 1) file the outside details of the truck side enough to eliminate interference with ladder, 2) bend the ladder outward enough to eliminate interference, 3) remove the ladder all together, 4) mod the ladder by removing then adding shims to move it outboard to avoid interference with the truck. I don't like options 2, 3, or 4. But before I get out my file, thought I'd see what you fellows think.