This spring pin secures a component within the grain tank unloading system of the parent harvester. It is driven into a cross-drilled hole to lock a shaft or linkage in place, preventing axial movement during operation. A worn or missing pin allows the retained part to shift, leading to misalignment of the auger or conveyor drive. The pin is manufactured to the original diameter and spring temper, so it holds its installed tension without loosening under vibration. On replacement, drive the pin fully into the bore until its ends are flush with the surrounding boss.