This synchronizer ring is a component inside the gearbox of the host tractor. It engages with the sliding hub and gear cone to match shaft speeds during a gear change, allowing the dog clutch to engage without grinding. When the ring wears, the shift becomes notchy or produces a grinding noise, and the gear may pop out of engagement under load. As an original AGCO part, the ring is machined to the same cone angle and friction profile as the original assembly, which the shift fork and hub rely on for correct engagement timing. On reinstallation, ensure the ring is free of burrs and that the hub slides freely over it before closing the gearbox.