Rudder Shims
A simple, easy & inexpensive fix is to slide mylar shim strips about 2" x 12" down the rudder post. Use drafting film from an office supply store. It comes in different thicknesses so you can pick the size that meets you needs. This procedure will remove most play unless badly worn. Shims need to be replaced every year or so. A $10 roll of film lasts a life time.This can be done with the boat in the water. (1)Place a clamp (ie. vise grips)on the rudder post above the packing gland. (2)Remove the rudder cap. (3)Slide three or four shims down the rudder post. (4) Replace rudder cap and remove clamp.The other option to rebuild the rudder tube with epoxy is very expensive and can only be done when the boat is out of the water.