Grinding Noise from Prop Shaft

[jim_thomsen]

UPDATE: I was able to take apart the flexible coupling and the problem is definitely in the rear shaft/bearing area. I was able to move the shaft back a short distance and turning it made the same noise.
It was too late to go into the water and see if anything looks different there. Tomorrow's project.

If not, then I guess I have a bigger issue...if it's the bearing can that be replaced while in the water?

Thanks everyone for your help.
Jim

[fstbttms]

Originally Posted by jim_thomsen

...if it's the bearing can that be replaced while in the water?

My guess is that you will need to be hauled to replace the bearing. You would have to slide the prop shaft out of the bearing and possibly cut the bearing out of the housing, which means you probably couldn't have the opening plugged while doing that.

[delmarrey]

Originally Posted by jim_thomsen

UPDATE: I was able to take apart the flexible coupling and the problem is definitely in the rear shaft/bearing area. I was able to move the shaft back a short distance and turning it made the same noise.
It was too late to go into the water and see if anything looks different there. Tomorrow's project.

If not, then I guess I have a bigger issue...if it's the bearing can that be replaced while in the water?

Thanks everyone for your help.
Jim

That being the case it sounds like the cutless bearing maybe spinning in the strut/support.

[Cheechako]

If the bearing has been roatating in the boat, you are likely going to need to haul out as it has worn the tube oversize. To get you "home", when you go in the water, if the bearing comes right out, maybe you could use underwater epoxy to secure it in place until you get to a yard...? I thought it might be the transmission output bearing , but I guess you have eliminated that..

[HappyMdRSailor]

Originally Posted by jim_thomsen

UPDATE: I was able to take apart the flexible coupling and the problem is definitely in the rear shaft/bearing area. I was able to move the shaft back a short distance and turning it made the same noise.
It was too late to go into the water and see if anything looks different there. Tomorrow's project.

If not, then I guess I have a bigger issue...if it's the bearing can that be replaced while in the water?

Thanks everyone for your help.
Jim

No matter what, it's the lesser of two evils.... Tranny intact where you are is a good thing!

[Jim Cate]

G'Day Jim,

Glad that it isn't in the tranny or damper plate... those parts might be scarce in Palau!

If the noise is from the cutless bearing turning inside the strut, perhaps tightening the set screws that secure the bearing MIGHT stop the rotation (if yours is in fact secured with such screws!). Also, if it is spinning it should be easy to remove without cutting anything, so if you could get the prop off, an underwater replacement MIGHT be possible.

A closer examination is obviously needed... again, good luck!

Jim

[Vasco]

Originally Posted by Jim Cate

G'Day Jim,

Glad that it isn't in the tranny or damper plate... those parts might be scarce in Palau!

If the noise is from the cutless bearing turning inside the strut, perhaps tightening the set screws that secure the bearing MIGHT stop the rotation (if yours is in fact secured with such screws!). Also, if it is spinning it should be easy to remove without cutting anything, so if you could get the prop off, an underwater replacement MIGHT be possible.

A closer examination is obviously needed... again, good luck!

Jim

If you try the underwater route in 80 feet lashing a cargo net or hammock under the stern of the boat might give a little peace of mind re the Gori. The small pieces might need a bucket.

[BoomBrake]

Hi Jim,

Hope you have successfully narrowed down the source of the problem and best likely solution. My search based knowledge of the Internetz, shows you currently somewhere near Malakal Harbour Palau. If this correct, apparently you can arrange (expensive) crane haul-out there:

"craning - Malakal Island (search Neco Marine Palau) and in Airai on the n/nw end of the big bridge connecting Koror and Airai."
Source: http://www.cruisersforum.com/forums/...hp?t-2371.html

Another yacht "Mowe" did restoration work there in Palau, like you guys they have an informative blog with contact details. Perhaps they can assist with local knowledge, parts, tools, haul-out, etc:

http://mowepalau.yachtblogs.com/2012...ulout-phase-1/
http://www.sailblogs.com/member/t37/

IMHO the rope tangle could have directly affected the cutlass bearing and/or the Gori prop folding mechanism (on your long motoring, prop blades did not evenly unfold), therefore further causing oscillation atrophy on the shaft alignment and bearings. Also similar to this cause-effect, some have experienced coral growth in the Gori prop blade mechanism:

http://www.syfuga.co.uk/20110531b.htm

I'm no expert, but I hope some of this info is of some help. Safe travels!

Cheers,
Marty (AKA BoomBrake)

PS Found these that also may help:
http://www.yachtsurvey.com/alignment.htm
http://www.yachtsurvey.com/Alignment2.htm

[Nicholson58]

Originally Posted by highseas

Jim Thomson, if you snagged a rope tight enough to break the linecutter,then you quite possibly also did internal transmission damage.Sometimes it takes a few more operating hrs. before grinding noises start.

I can't say for sure but I don't think the coupling will transmit tension; perhaps thrust. If the engine was stalled abruptly then there might be torsional impact to the machine. Inspct the heck out of it as you disassemble from the rear and hope you find a broken key or coupling element.

Once the engine and trani are seperated from the prop shaft you will be able to isolate the source. Even if its internal to the transmission you might get lucky and find a sheared key mounting a gear to a shaft. Lots of photos.

[jim_thomsen]

Thanks everyone! Boombrake, good to hear from you again (thanks for all the links!). I did talk with the crane operator today and he thinks they can lift us. But we are a couple tons more than the heaviest they have lifted so far. We will also have to take down the mast and build our own cradle. All possible, not easy, probably expensive.

But today I pushed the shaft out as far as possible and put on a lot of grease underwater, then back in and put more grease inside, then repeated and now it seems to be quiet.

Did I correct the problem? Should I just assume it's fixed? I may repeat the operation tomorrow anyway, but hauling out is a big, risky deal so I would like to believe it's now fine. But leaving here we motor 15 miles through narrow reefs and then reaching the Philippines we have narrow channels, fast currents and whirlpools, so I want to trust our engine.

If you were me, would you assume it's fixed and head off for the Philippines?

Thanks,
Jim

[Sailmonkey]

When you pushed it back could you see any of the cutlass!

I'd do a few laps around the lagoon to test it.

[fstbttms]

You greased the shaft and/or bearing?

[BoomBrake]

Great to hear from you too, Jim.

I too am a little confused about the application of grease. The little I know about modern Cutlass Bearings, is they are made from special rubberised plastic compounds that are incompatible with petroleum based grease. The only lubricant they need is sea water and a anything else could be an issue. (here come the links):

http://www.stevedmarineconsulting.co...index.php?p=47
http://www.cruisersforum.com/forums/...ent-65724.html
http://forums.sbo.sailboatowners.com...ad.php?t=85722
http://www.pbase.com/mainecruising/replacing_a_cutlass

If the Cutlass Bearing is indeed the source of the problem and you want to be sure and safe, haul-out and replace the Cutlass Bearing. Anything else is not 100%. Certainly expensive, but cheaper than hitting a reef. Where the shaft meets the Cutlass Bearing, needs to be clean and free of impurities. I don't think changing underwater is an option. I'd also use the opportunity to double check the shaft alignment.

Again, I'm no expert, but have read all the above as such. If you need any procedures or questions answered, I'd be happy to run this by the Darby and the boys at the marina if you need. Let me know.

Cheers,
BoomBrake

[delmarrey]

W/o pictures it's a bit difficult to tell what you have.

Grease may present more of a problem then a cure in a long run. Cutless bearings have longitudinal groves which allow water to pass thru, in turn lubricating and cooling the bearing.

If those get plugged, the bearing could over heat and cause even more wear on the parts. And I'm not sure grease would stay in a strut hung bearing for very long anyway.

And if it is a spinning cutless bearing it needs to be secured in place some how even if you have to drive tiny wedges/nails between the bearing and strut. Or like stated earlier, tighten the set screws, if it has them.

Can you explain in some detail what your drive consists of from the coupler aft?

[motion30]

perhaps it was just marine growth between the shaft and bearing