Vibration Noise

[Dan Miles]

I have had this C30 for 2 yrs and have always noticed a harmonic type vibration noise when motoring. It is not the engine noise but like something knocking on the fiberglass in the back half of the boat and you cannot tell where it is coming from. After Ivan repairs and engine alignment the noise is even more constant. The Catalina dealer said that is just part of a C30. Well it is very annoying. Someone named John Olson addressed this problem and said he made it much better with a "rudder drive line damper". Does anyone else have this problem and/or know about the rudder drive line damper? Thanks, Dan Miles

 

[Eric Ludin]

I had the same problem

I have an older C30 (1983 vintage). I had the same noise that was only apparent when the boat hit 2500 rpm. It was quite loud and forced me to back the throttle to 2400 rpm. It didn't happen when the boat was docked and I ran the engine up, in gear. It only happened when underway. Someone suggested I remove gear from the lockers as something stored there may be vibrating against the hull. That didn't work to solve my problem, but might be your problem.When the boat was hauled, I learned that the fiberglass holding the strut had cracked! I had the strut reglassed in place and the vibration went away. It was not an easy job. You have to remvove the fuel tank to access the strut from the inside and cut away the cracked fiberglass from the outside. But, I let the yard do it and I was pleased with the outcome. Since my boat was older, it gave me a chance to clean out the fuel tank and get rid of the sludge that collects on the bottom.

 

[JohnOlson]

Hay Dan

I just receved the new WM cat and Im looking at the page with my vibration damper its a R&D flex coupling model3684883 or3684891 i couldnt figure out witch one to by so i bought both and im not sure witch one i used but it just fit and i need to remove it to repack my stuffing box and it is still working great.I have a new thing to try .start motering at about 2200rpms and start to tighten your backstay on flat water and listen to the sound of the boat go to your max rig tension and see if the noise changes when .Mine went away when the rig got tightand sailed better .The boat has alot of flex when the rig is not tight and it changes how it sits in the water