I am noticing a slight flutter movement in the steering that seams to be coming from the rudder . It occurs when the rudder is in a neutral bearing between port and starboard . Last time the boat was hauled there was a very slight amount of play in the rudder shaft. No one at the yard seamed concerned , two years later i am noticing the new flutter. Does anybody have experience with this, Is there a way to tighten up the rudder shaft without hauling the boat ?