G23 Vibration

[blueroom]

I have started to notice a vibration, like something is slightly out of balance. It isn't terrible and I don't think you can feel it in the boat, but more in the steering wheel. At speed it just feels a little less smooth. I started to feel this the last time out, and it seemed worse today. I haven't had any prop strikes that I know of, and we have been surfing a lot since I first noticed it (so I don't think it is the shaft going).

Any thoughts? Do props ever just get out of whack?

[charlesml3]

No, props do not "just get out of whack." There are several possibilities:

- You have something wrapped around the prop.

- You hit something big enough to ding the prop, but not so big you really heard it hit. Examine the prop CLOSELY. Even a small ding will cause it to vibrate.

- Your driveshaft is cracked and you're on the verge of having it shear off.

[blueroom]

With another two days on it, it still has not let loose - so I don't think it is the shaft. We have been trying to hunt it down and the prop seems OK.

The vibration is all of a sudden is really bad. You can now feel it all around the boat and at times is audible. If you run with ballast at wakeboard speed and crank a starboard turn vibration turns to a shudder. We cut things short this evening as I don't want to damage anything.

Going to be taking it in to the dealer, but thought I would check back and see if any more ideas. I wouldn't think a prop vibration would just get worse on its own. You can run the engine with the prop disengaged and it runs smooth. I guess it could be a shaft issue, but those seem to go pretty quickly when they go.

Shaft strut bearing failing? Packing going? Something loose?

[charlesml3]

Shaft strut bearing failing? Packing going? Something loose?

Could be strut bearing. Not packing. Packing would not cause this.

Grab the rudder and see if it has excessive play in it. That could cause vibration.

-Charles

[thejean]

My buddy had this exact same issue with his X23. Turned out his prop was missing a blade and the strut was cracked. But only one blade was damaged and it took a long time to actually break off and the vibration just got worse and worse until it eventually broke completely (and I happened to be behind his boat surfing when it happened). It’s not going to be covered under warranty either which sucks for him.

[blueroom]

The prop looks solid, the shaft is tight in the strut, no signs of shaft fatigue, etc. The rudder has a little play, but not a whole lot more than a new boat.

Evidently, it is not uncommon that the engines settle, causing mis-alignment. I looked and the the owners manual recommends checking shaft alignment at 25 hours and every 100 hours. Boat goes in on Wed and, short of finding something obvious, they are going to start with checking engine mounts and work through the drive components to make sure things are where they should be. Then we water test and see how it works.

[Tom_H]

You can do a bit of diagnosis with a piece of solid gauge wire. Tape it to the bottom of the hull and you can use it to check the shaft and prop. Point the tip of wire at the center of the shaft, and spin the prop by hand to check for shaft alignment, or if there is a bend. If the shaft relative to the wire stays put, shaft is alright. Then do the same thing by putting the tip of the wire at the tip of a propeller blade, and again spin by hand. If any of the blades are a different distance away from the wire, your prop has an issue, and you can do this with leading and trailing edge of the prop. Obviously, this isn't perfect, but it will detect minor prop variances that you won't see by eyeballing it, but can cause big time vibration. In your case I'm betting rudder or alignment issue.

[blueroom]

Ended up being shaft coupling. Separate post made letting people know to occasionally check coupler bolts.