You should check the underside of your rudder bearing housing (see attached schematic) and make sure a short (3" to 4") tube is fiberglassed to the underside of your rudder bearing housing.
I own a 1992 C34, hull number 1204, and the tube is missing. I contacted Catalina and they do not recall other C34's missing this component and sent me the tube so I may fiberglass it to the underside of the rudder bearing housing myself.
Last summer we were crossing Lake Michigan, returning from the Queen's Cup. The trip was roughly 65 miles starting from Muskegon, Michigan to our home port of Sheboygan, Wisconsin. The wind was blowing 25+ knots and was right on our nose, so we elected to motor directly into the wind and waves. After two hours of heavy pounding in growing seas (8 footers), we decided to fall off and raise reefed sails and take the long route home in order to avoid the punishing pounding the boat would take each time it descended a wave. We took a reef on the main and genoa the boat sailed beautifully gliding up and down the waves without the pounding.
After about four hours of sailing we were literally in the middle of Lake Michigan and the helmsman said "I feel a clicking or tapping under my feet every time boat moves from side-to-side". We looked at each other, our eyes got big and we knew this was not good news. We immediately removed the rudder post cover just aft of the pedestal steering, and there we saw the top of the rudder post moving back and forth 3/16's of an inch each time the boat rocked from side to side. Our concern then focused on the integrity of the rudder post tube that goes through the bottom of the boat. We grabbed our spot light, opened the rear hatch door and observed the rudder post tube where it attaches to the boat's hull. This rudder post tube that attaches to the bottom of the boat is roughly 18 inches high. It encompasses the rudder post as it passes through the bottom of the boat and it is higher than the water line and has packing on the top to keep water from enterring the boat.
We observed that the rudder post tube was flexing each time the top of the rudder post rocked 3/16's of an inch with each wave. Our concern was the 50 degree water, that we were 29 miles from land and what would happen if the flexing of the rudder tube would start to crack where it attached to the hull (i.e., water starts to flood the boat). We called the Coast Guard and requested they escourt us the rest of the way to our home port. Fortunately the rocking and flexing of the rudder post never created a crack where where the rudder post tube attached to the bottom of the boat. The Coast Guard arrived in one hour and 45 minutes and escourted us the rest of the way home.
Check to make sure you have a short rudder post tube (it should be 3 to 4 inches long) and should be attached to the underside of the bearing housing (see schematic). Our boat never had this tube attached and the pressure from the rocking compromised the bearing housing. It no longer fit tightly around the top of the rudder post so the top of the post began to move back and forth as the boat rocked with the waves.
Here is to safe sailing.
Miles H