This lower kingpin pin connects the steering knuckle to the axle housing, forming the pivot point for the front wheel assembly. It carries the vertical load of the machine and transmits steering forces from the tie rod to the wheel hub. Wear on the pin or its mating bushings introduces free play in the steering linkage, which causes imprecise directional control and accelerated tire wear. The pin is machined to match the original bore tolerance in the axle housing and knuckle, so no additional shimming is required during installation.