Can the location of the propeller shaft zincs on the shaft cause vibration?
Recently, my Starboard aft has began to vibrate at 2800 rpm's.
My bottom cleaning service tells me that my props need to be pulled and tuned up at a propeller vendor. Another diver tells me that the zincs may not be placed in the correct location, although I am getting vibration on just the Starboard side.
Boat in 1989 Tiara Open with 8.1 L Crusaders.
Can club members give me some advice?
You may want to check and change if needed your strut bearings I just did mine after 450 hrs. not that bad of a job if you have the puller to do it with.
May I ask if you were having vibration problems before you changed the strut bearings?
If so, did the vibration stop after you changed the strut bearings?
Strut Bearings: changed when the boat is hauled out or in the water?
Thank you, Mike
I had slight vibration and found the strut bearings showing signs of wear so installed new out of the water I don't believe you can do it any other way. After the boat is put back in the water this spring after the boat has taken its natural shape I will allign both motors and sea trial. Hope this helps.
Thanks for sharing your experience. I will talk with my mechanic about the bearings and include it with my next haul out. Expecting to Repaint the bottom in the fall. Plan to address the bearings and tune the props at this time. Was out on the water yesterday fishing. Smooth until I hit 3000 rpm's and then some vibration on the starboard engine, at 17knots. I can live with it till the haul out. Best regards, Mike
Can shaft anodes cause vibration? The short answer is yes. The long answer is it is unlikely they are the direct cause of the vibration.
If the vibration just appeared out of nowhere, meaning you did not hit or strike an object, then it is mostly likely one of two things happened: 1) The cutlass bearing is worn and the shaft is now moving around within the strut housing causing the vibration. Cutlass bearings are wear items and have to be replaced from time to time just like the brake pads on your car. If you run in clear, calm water and your engines are properly aligned and your shafts and props are balanced, your bearings should last 3 to 5 years. Running in rough water, turbid water, or if your engine is out of alignment or something is off balance will cause your cutlass bearings to wear faster. Going back to your original question, if the shaft anodes slide back and block the water flow to the cutlass bearings, this can rapid wear to the bearings. So indirectly, yes, shaft anodes can cause vibration in the form of premature bearing wear. 2) The other possible out of the blue vibration issue could be an engine shifted and is no longer aligned. Running in rough water can cause an engine to shift alignment. A loose engine mount bolt can cause an engine shift. Storing a boat out of the water on a couple of keel blocks and some jack stands for extended periods can cause the engines to come out of alignment. A proper supporting cradle would be a better way to store a boat out of the water.
I hope this gives you a little better understanding of vibration, although the above is by no means a complete list.
Good luck and let us know how it works out!
Thanks Chris! As always, your expertise is appreciated. Hauling out on March 4 to paint the bottom. Yard will check the bearings, replace if necessary. I have no record that they have been changed since 2010. Mic and laser measure the shaft. Pulling the props for re-tuning at prop shop.
I did have the prop on the side that vibrates get tangled in a rope from a lobster trap in October, 2013. I shutdown the engine immediately and we cut the rope away. Vibration started last Spring. 2014. Starts at 2800 rpm's. Smooth under that speed. We do have some rough water crossings between Long Beach and Catalina.
Will update my post after the work is done. If the above does not correct the problem, I will have my mechanic check the mounts and alignment. Mike
Loose Prop can certainly cause vibration as well! Let us know.
Decided to go with new strut bearings and reworked props; without doing the realignment of the engines recommended by the yard. Prop Shop found bent blades and very unbalanced props. Finished prop work with very little difference between the props.
Fished offshore yesterday, about 12 miles, 03/21. Boat ran very smooth cruising at 3200rpm's 20 knots flawlessly with no vibrations. Pushed it up to 3800 rpm's at 25 knots, all good. Next trip will try max throttle to fully check it out.
Keep engine realignment in my back pocket and use my own mechanic at $85.00/hr. Rather than yard rate $120.00/hr.