That's the pin. Drive it out an replace it. Find a nail that's the exact same dia. It doesn't have to be hard steel. It should be soft so it wears in and operates smoothly. The piece that is round with a triangular shaped end may also have a lot of wear. In that case, go to the wanted section of the forum and ask to buy one. It's a super common item. A couple of bucks should get you one. There is only one size as far as I know. Gary