Eccentric Crank posted:
I have a Lionel CSX SD-40-2 from some few years ago. The frame is straight. I just looked at it a bit (hard to get to at the moment), and the frame appears to be sheet steel, the common construction method for O diesels, pretty much forever in the modern era, covered with a plastic diamond non-slip surface.
This sheet steel can be easily bent (in shipping or even by the packaging method itself), and bent back into shape with, usually, careful hand pressure. This steel is relatively malleable. I have corrected the bent frame issue before on some Atlas SD40's (of all things) with some judicious pressure.
This may not be your answer; I have never had to work on my Lionel SD40-2, but it certainly has happened to me here and there with other pieces.