I am rebuilding a 12jc pump for the first time and have noticed quite a bit of wear on the shaft where it contacts the packings (just forward of the thrust bearing). Anybody have suggestions on how much wear is acceptable before the shaft should be replaced? Would using a graphite/rope style packing make an effective seal? :idea: I am not made of money but want the rebuild to last. This is a family/pleasure boat, not a racer.