Cutlass Bearing Failure

[rms95835]

Our 2010 Jeanneau 42i had the P bracket (prop strut) replaced about 1 year ago. All was well, up until we had to leave the boat in the DR in May of last year. Upon returning, and transiting from Puerto Plata to Samana, the cutlass bearing has failed. There is slop approaching 1/8th of an inch on the prop shaft. There are about 60 hours run time since the parts were replaced, so trying to figure out why a part that typically lasts years, has failed so quickly. My only thought after diving the boat and diagnosing the failure is the line cutter that is installed between the prop and the P bracket is mounted too close to the P bracket and is not allowing water to flow through the cutlass bearing and provide lubrication. Any thoughts would be greatly appreciated.

[Training Wheels]

If the boat sat idle, perhaps you got hardshell fouling in the grooves of the cutless. It can quickly deteriorate your cutless, kind of like sandpaper.

[rms95835]

Training Wheels.......you may have the answer to this situation. Makes perfect sense based on our experience. Sucked for more reasons than I can begin to explain here to have to leave the boat for 9 months.

[seahag]

Looks like you found the "slop" while diving? How--wiggling underwater, and you can feel the 1/8" movement? Yikes. Were you getting a lot of vibration?

[rms95835]

Hi Seahag.......must tell you pains me a bit to address a fellow sailor that way, but as you wish. We had lots of vibration immediately. Spared use of the engine, and when we had to used very low RPM. Things smoothed out a bit where we made it to our next stop (sailed from Ocean World to Puerto Bahia, DR). Once we got to our slip at Puerto Bahia, I dove and checked out the situation. I could move the shaft laterally inside the strut bearing approx. 1/8", a lot more than it should be. I've had a couple of responses that make perfect sense for my situation (9 mos. at Ocean World sitting) regarding something forming on the shaft in the cutlass bearing grooves due to the inactivity, then tearing it up when I put the boat in gear. Now just hoping the repair plan that will start tomorrow will work. 🙏🏽🙏🏽🙏🏽

[seahag]

Well, that is a bummer for sure. So many things just do not last it seems. Just sitting for a few months shouldn't do this, but then again in a hot climate I suppose anything could happen. Do you think your alignment was good to begin with?

It will be interesting to see what you find tomorrow. I'm really wondering what that bearing is going to look like. It almost seems like something wasn't right with the install.

[kmacdonald]

The shaft is out of alignment. Looks like the prop strut was not aligned correctly. Fouling in the cutlass bearing grooves will not cause it. Fouling is cleared as soon as the shaft stars spinning.

[rms95835]

Not sure if it may be related, but have attached a picture of what the seal looks like where the prop shaft goes through the hull. It seems to me it is likely a cover, but not knowing, I'm hesitant to remove the two clamps that are holding it in place. Any ideas??

[Training Wheels]

Originally Posted by rms95835

Training Wheels.......you may have the answer to this situation. Makes perfect sense based on our experience. Sucked for more reasons than I can begin to explain here to have to leave the boat for 9 months.

I know of several people this has happened to. Options are to put some grease around the ends of the cutless, or secure a plastic bag around it (just don't forget to remove it!).

[leftbrainstuff]

Other than a regular drip indicating water lubrication it's very difficult to assess pending failure in a cutlass bearing.

We prefer the PSS shaft seal which is much easier to assess at rest and while running. If its dry it will squeal. It's also permanently wet.

[rms95835]

Sorry, pic didn't attach.

[seahag]

That's your stuffing box. Keeps the water on the exterior side of your boat. Keep the clamps on for best results. Here's a good article link: http://www.windcheckmagazine.com/stu...ox_maintenance

[svHyLyte]

Originally Posted by rms95835

Not sure if it may be related, but have attached a picture of what the seal looks like where the prop shaft goes through the hull. It seems to me it is likely a cover, but not knowing, I'm hesitant to remove the two clamps that are holding it in place. Any ideas??

Ah... That is a standard issue Volvo shaft seal, used in place of a "Stuffing Box" type seal or one of the various "dripless" shaft seals. he two hose clamps hold the seal in place on the shaft log (the shaft gallery or tube through the hull). You really don't want to loosen the clamps with the yacht in the water or you'll have a lot more to worry about than a worn cutlass bearing. Squeeze the end of the rubber and inject a little non-petroleum grease into the gap between the shaft and the inner lip seals using a flattened drinking straw partially filled with the grease, from time to time but otherwise, leave the thing alone!

There are two points of support on your shaft--the flange connection at the transmission and at the shaft strut where the cutlass bearing is installed. The engine must be aligned vertically fore'n-aft such that the shaft (assumed to be straight) passes directly through the longitudinal center of the shaft strut (sometimes referred to as a "P-Bracket")/cutlass bearing. If that alignment is off, or if the shaft is not straight, or if some lame-brain has attached a shaft zinc too far from the shaft strut between the strut and the shaft log such that the shaft "whips" in rotation because of centrifugal force generated as the shaft rotates due to irregular wasting of the zinc, the cutlass bearing will wear away quickly. These days, with laser alignment gear readily available, there's no reason that an engine cannot be adjusted for good shaft/shaft strut/cutlass bearing alignment (especially considering we used to manage that with a ball of twine and a couple of chop-sticks!).

FWIW...

[Pete7]

Originally Posted by svHyLyte

or if some lame-brain has attached a shaft zinc too far from the shaft strut between the strut and the shaft log such that the shaft "whips" in rotation because of centrifugal force generated as the shaft rotates due to irregular wasting of the zinc, the cutlass bearing will wear away quickly.

You will excuse me whilst I quietly leave the room

[rms95835]

SvHyLyte..........Thank you for the response and ID of the type of shaft seal. We are dry with the shaft stationary, but getting an excessive amount of water when the shaft is turning. I'm happy to give the non-petroleum grease a shot to see if it helps. Can you give me an idea of a brand/type you have used successfully? Am assuming if this doesn't fix the issue, it's time to schedule replacement of the seal? Appreciate very much your time and information. Have found this forum to be filled with people willing to help, and it is appreciated!