This spacer disc sits between components inside the gearbox to maintain the correct axial clearance between rotating and stationary parts. It functions as a shim that controls end-play on the shaft assembly, preventing gear clash and ensuring smooth power transmission through the drivetrain. A worn or missing disc allows excessive shaft movement, which produces a knocking noise under load and accelerates bearing and gear wear. The original AGCO part is machined to the same thickness and bore dimensions as the factory-installed shim, so no stacking or measurement adjustment is needed during replacement. On reinstall, verify that the disc seats flat against the shoulder and that the retaining nut is torqued to specification.