Reply to "Lionel/AF '94ish 6-48048 SD-9 engines won't pass over traditional AF rerailers"

I  have the Canadian National GP-9 from that era and it does the same thing.  On mine, it is the screws holding the sideframe assembly on.  Instead of being flush with the bottom like postwar diesels, the screw heads stick out and catch on the center of the re-railer.