This lower link ball is the pivot point connecting the tractor's lower hitch arm to the implement's hitch pins. It sits in the ball socket of the three-point linkage and allows the implement to pivot freely during turns and on uneven ground. A worn ball creates slop in the linkage, leading to uneven implement tracking and accelerated wear on the socket and retaining hardware. This replacement component is machined to the same outer diameter and inner bore dimensions as the original, so it seats correctly in the hitch arm without requiring shimming or modification. On installation, ensure the retaining clip or cotter pin is fully seated and the ball rotates freely in its socket before attaching the implement.