Vibration of Prop/Shaft While Sailing

[Jim Satterfield]

I am the new owner of a Catalina 36/1983. It has the factory engine, 25HP Univ. Diesel. The owners manual says to leave the transmission lever in neutral while sailing. When I do this, and get over 5+knots, I get a vibrationfrom the shaft/prop. It is especially so when at 7+ knots. I can put the gear shift in reverse and the vibration stops. I do not have a vibration problem when motoring.Any ideas what is going on?

 

[Jon]

Prop Vibration

According to my Universal MXP25 Manual, either neutral or reverse is acceptable while sailing. Neutral to allow the prop to spin, or reverse to stop the spinning of the prop. I'm not sure what is causing your vibration problem, but reverse to stop the spinning is the preferred solution as it promotes less drag while sailing.

 

[John Mavrovich]

Reverse

I'd keep it in reverse when sailing.

 

[Steve Franklin]

Shaft vibration

Info I've seen for C30 w/ Universal 5411 emphasizes importance of sailing with transmission in reverse. Supposedly forward and especially neutral can cause "polishing" of the clutch, resulting in performance and maintenance problems. I'm not willing to gamble, so I sail with the trans in reverse. Happy sailing!