Rudder Vibration - Left-hand turns

On my '94 Ski Nautique (500 hrs) I have this loud vibration coming from my rudder when I make left-hand turns going over 30 mph. It's quiet going straight or when making right-hand turns at this speed but when turning left it makes a pretty lound noise. At first I thought it might be the shaft or prop but it's definetly the rudder.

When out of the water I can move the rudder about 1/8" back and forth. Can this be tightened or is it worn?

Thanks,
Keith

May just need a turn on the packing nut. Or new packing material. Can't quite remember, but I thought you could shim the rudder up/ down by using washers...it's been a while...

Hi

Not sure of your set up Keith,but I like to see a safety collar on top of stukking box.If you get a split collar you can force it down the rudder shaft to get all up and down play out of the rudder,this will usually stop any vibs from the rudder.

Good luck Munday

behindpropeller wrote: Did that on the other 90's CC's i drove. Even when it was brand new.

The vibration he's experiencing is definitely not normal.

I checked my rudder. There is virtually no play up-down, fore-aft, or port-stbd. There is about 0.2" play in what I assume to be the steering linkage left and right measured at the trailing edge of the rudder.

For comparison, I looked at the rudder on my '85 Ski Supreme sitting next to it which has about 1/4' to 3/8" play in all directions and I don't ever remember it having the type of vibration we seem to be having.

I did a quick check of the prop shaft alignment a month or so ago when replacing the shaft packing, and noticed that my strut bearings are worn. Do you think that could be the issue?

I first thought it was the shaft bushing but I have zero play in the shaft. I also pulled the floor and laid down with my ear back there and feel pretty confident it's the rudder.

Before I said 1/8" of play in the rudder, it might be more like 1/16" - not much as all. That's lateral play. Vertical play is probably 1/32".

I hope to have the boat over to Brad's (Barracuda) house next week where Tim (TRBenj) and Brad can take a look at it for another opinion.

I can live with the noise this season, just want to make sure I'm not doing more damage.

-Keith

Hamilin, let us know how this goes. I will be trying out a new prop in the next week or two. We'll see if this makes it better.

-Keith

Great advice! When I take the GF out on the next "evening" cruise I'm using the bent prop.

There is definitely more noise turning to one side in all inboards. This is due to increased pressure caused by the rotation of the prop in combination to the forces from the boat turning. When turning with the rotation of the prop (let's see ... left turns with right-hand rotation or right turns with left-hand rotation. I think that's correct), the shaft will rub against the hull and/or against the strut bushing more than when going straight.

My issue is not normal however. It seems far too loud. Woodie at SECC thinks it could be my prop putting out irregular turbulence. Tim is going to let me borrow one of his props to see if it goes away. I'll let everyone know what I find.