This reverse synchronizer ring is the component that matches the rotational speed of the gearbox input shaft to the target gear during a direction change, enabling the tractor to shift from forward to reverse without gear clash. It sits inside the synchronizer assembly on the reverse-gear side of the transmission. The ring’s internal teeth engage with the synchronizer hub; when the shift collar presses the ring against the cone of the target gear, friction synchronizes the speeds before the collar slides fully into engagement. A worn ring loses its friction surface, causing grinding during engagement and eventual inability to complete the shift. As an original AGCO part, the ring is machined to the same cone angle and tooth profile as the original assembly, so it maintains the correct axial clearance and engagement timing without shimming. On reinstall, ensure the ring is oriented with the friction face toward the cone and that the shift fork is properly aligned.