Delrin is considered a self lubricating material. Grease during assembly is all that’s needed. It’s hardness prevents noise unlike urethane that’s softer.
My pins aren’t drilled as that weakens the pin and as mentioned, greasing isn’t necessary after assembly. My pins are the same Rockwell hardness as the originals. The pin is sized for the ID of the bushing already. This provides a round surface for the bushing to ride on. Same with removing the outer shell from the arm. A round surface is left for the bushing to fit into.
