The ornamental design for a railroadcarcouplerassemblyknuckle pin, as shown and described.
FIG. 1 is a first front perspective view of a railroad car coupler assembly knuckle pin showing my new design.
FIG. 2 is a second front perspective view of the railroad car coupler assembly knuckle pin.
FIG. 3 is a front side view of the railroad car coupler assembly knuckle pin.
FIG. 4 is a rear side view of the railroad car coupler assembly knuckle pin.
FIG. 5 is a right side view of the railroad car coupler assembly knuckle pin.
FIG. 6 is a left side view of the railroad car coupler assembly knuckle pin.
FIG. 7 is a top view of the railroad car coupler assembly knuckle pin; and,
FIG. 8 is a bottom view of the railroad car coupler assembly knuckle pin.
The broken lines shown in the drawing views illustrate portions of the railroad car coupler assembly knuckle pin that form no part of the claimed design.