I have a '77 4 speed FLH. In the JP catalog there is a listing for a clutch push rod. These are of varying length and appear to be threaded on the end. There is no mention of this part in my Clymer or HD manuals. Could these be called something else? I don't seem to get enough throw from my clutch, so the plates tend to grab. It may be the one I have is a little short (that's the story of my life). Can these be easily unscrewed and replaced? Thanks