Side frame-bolster interface for railcar truck assembly

A three-piece railcar truck assembly is disclosed. The truck assembly has two side frames and a bolster extending between the side frames. Each side frame has spaced columns defining an opening which receives one end of the bolster. Each side frame also has forward and rearward lugs at the columns, both on the inboard side and the outboard side. Each side frame lug has a stop surface that is aligned in a facing relationship with a stop surface of one bolster gib. There is a gap between the opposed side frame lug and bolster gib stop surfaces. The gap distance is limited to limit the truck warp angle. The neighboring side frame lugs and bolster gibs may be sized, shaped and spaced so that the truck warp angle may be limited to an angle of less than two degrees.