Trying to drop my rudder out for repair, but cannot get the rudder post cap off. Have removed the horizontal bolt and squirted PB blaster in the holes without effect. Have put a 2 foot breaker bar in the emergency tiller receptacle while the rudder post was clamped with a vise grip and cannot break it loose. Is the cap threaded onto the top of the rudder post? Tried rotating it clockwise and counterclockwise with a great deal of force without it breaking loose. Also tried bouncing the rudder up and down without success. Last option will be to heat the cap with an acetylene torch but the nylon bearing fiberglass could easily get damaged. Any advice?