This spring provides the return force for the clutch mechanism inside the combine header. It acts between the clutch pressure plate and the release bearing, disengaging the drive when the operator activates the header clutch. A fatigued spring reduces clutch release pressure, causing the header drive to slip or fail to disengage cleanly. The manufacturer machines this spring to the same free length and rate as the original assembly, so the clutch pack engages and releases at the correct pedal or lever position. No shimming or adjustment is needed on replacement.