Originally Posted by Capt.Bill11
Looking at the picture I'm not sure why you'd need a jam nut. The Clevis is pinned to the rod with a cotter pin. So there is no way it or the rod can rotate.
There is slop between the clevis and rod, whether from age/wear or original misfit. It translates to a very small wobble in the rudder if you twist it. Everything else is new, fixed or cleaned up so I'd like this to be.