I'm curious how many of you are experiencing a knocking noise from the front spring pins? I have 4 buses i know of that are doing this. I can stand on the bottom step and rock the bus back and forth and re-create this problem. I have found no rust trails from the body mounts and I can feel the knock in the spring pin. These are the non-greaseable pins on a Blue Bird transit. Do you know if they make a greaseable pin replacement? Thanks.