This pin connects the lower-link arm to the tractor's three-point hitch assembly. It passes through the clevis eye of the link and the implement's hitch bracket, transmitting drawbar forces from the tractor chassis to the attached implement. A worn pin creates slop in the linkage, which causes uneven implement depth control and accelerates wear on the bushings and clevis bores. The pin is machined to the original diameter and hole spacing so that the hitch locks securely without shimming. On installation, ensure the retaining pin or clip fully engages the cross-hole to prevent the pin from walking out during operation.