This metal washer goes under the 34065-52 hollow bolt that holds the cam plunger, which pushes against the cow paddy shifter plate.
The bolt, or Retainer, cam follower, as the factory calls it, holds the shifter plate in the gear positions, as well as having a detent for neutral.
|The Iron Sportster trap door assembly holds the mainshaft, countershaft, and shifter mechanism.
Sportster 34168-52 shifter cam lock tab. You use a new one every time, and bend the one of the little tabs against the bolt head to lock the bolt in place.