The rocker arm assembly has an anti-inversion part that prevents a support pin from inverting, ensuring proper orientation of the support pin, on which a rocker arm is rotatably mounted, is maintained. The anti-inversion part can be a washer, a plate, a plug, or a sleeve. The washer, which has a flat face and a curved face, is intended for use with a cylindrical support pin which matches the curved face of the washer. The plate can include various combinations of tabs, flanges, and/or protrusions that extend in different directions. The plug can resemble any desirable shape, and is removed prior to final assembly. The sleeve can be hollow and is removable.