The Shift Drum / Shift Fork 81-82 assembly is constructed from several parts from which the Drum,gear.shift is the most expensive.
Parts such as the Shift Drum / Shift Fork 81-82: Washer Setting, Spring,plate, Spg,drum Stopper, Cam Gear,shift are included in the Xr500r 1981 (b) Usa Shift Drum / Shift Fork 81-82 parts fiche.
In this schematic the "22x2thrust Washer" is used most often.