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-   -   Early Cutlass bearing wear. Is this a problem? (http://www.sailnet.com/forums/general-discussion-sailing-related/87218-early-cutlass-bearing-wear-problem.html)

GrahamO 05-09-2012 01:24 PM

Early Cutlass bearing wear. Is this a problem?
 
The boat we are in the process of buying apparently has some play in the cutlass bearing (preliminary survey report). This would not normally be a big deal but the bearing, shaft and engine were replaced in 2009 and the engine has apparently only done 65hrs since then.

The surveyor does not seem overly concerned and feels that it might be a slightly out-of-balance prop (which we intend to replace at the end of this season anyway).

My concern is the possibility that this is an indicator of a more serious issue. If so are there any tests we can do to check this out more thoroughly? The boat is now in the water.

Thanks a lot,

Cruisingdad 05-09-2012 01:44 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Is the engine properly alighned with shaft? Seems to me that a cutlass going out that quickly on a sailboat which does not have high RPMS (and likely not a lot of engine use) would be a concern for me.

65 hours? That thing is brand new.

I am no expert. I am just giving the thoughts coming off the top of my head. BTW, that should all be fixable, so I would not make it a deal breaker. You just need to find out why. My first guess is an alignment problem.

Brian

T37Chef 05-09-2012 02:00 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Check the engine mounts, I suspect alignment issue as well, but thats just a guess based on my experience with a similar issue I had.

Faster 05-09-2012 02:01 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
In-the-water is the best time and place for an alignment check anyhow.. so split the coupling and use a feeler gauge or even just a clean piece of keystock to see if the clearance is similar (very) all the way around. Gross misalignment will be evident without the need for .005 inch feeler gauges.

casey1999 05-09-2012 02:25 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Quote:

Originally Posted by GrahamO (Post 869234)
The boat we are in the process of buying apparently has some play in the cutlass bearing (preliminary survey report). This would not normally be a big deal but the bearing, shaft and engine were replaced in 2009 and the engine has apparently only done 65hrs since then.

The surveyor does not seem overly concerned and feels that it might be a slightly out-of-balance prop (which we intend to replace at the end of this season anyway).

My concern is the possibility that this is an indicator of a more serious issue. If so are there any tests we can do to check this out more thoroughly? The boat is now in the water.

Thanks a lot,

Does surveyor reccomend replacing the cutlass bearing?

My boat also had play in the cutlass as noted by surveyor during purchase. He also was not concerned (although my bearing was very old unlike yours). My bearing/shaft probably has 1/16 inch play. I will replace on next hull out. I should have replaced when I had the survey, but survey said it was ok.

As others have said, I think you are ok. Replace bearing, check engine mounts and allign- should be good to go.

What is the failure mode from a worn cutlass bering?

Cruisingdad 05-09-2012 02:37 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
BTW, when our prop got junk on it, we felt vibration at low rpms. Did you feel that on your test sail?

Brian

Faster 05-09-2012 02:44 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Quote:

Originally Posted by casey1999 (Post 869263)
What is the failure mode from a worn cutlass bearing?

With longish shafts and a sloppy cutlass bearing you can develop 'whip' that would be mainfested as some unusual vibration, most likely only at certain RPMs or beyond certain RPM thresholds. If the rubber is truly gone, then you will get the grinding noise and rapid damage to the shaft and the bearing shell.. don't think it often gets to that stage, though.

GrahamO 05-09-2012 02:48 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Quote:

Originally Posted by Cruisingdad (Post 869269)
BTW, when our prop got junk on it, we felt vibration at low rpms. Did you feel that on your test sail?

Brian

Not at that stage yet Brian,
She has just been floated and is going for a topsides paint job. After that they will step the mast and we will do a test sail with the surveyor. He seems very capable and he does not think it needs action until we change the prop at the end of the season so I don't think this is serious but we will look at the alignment as described.

What a lot to learn.....

Thanks

casey1999 05-09-2012 03:24 PM

Re: Early Cutlass bearing wear. Is this a problem?
 
Quote:

Originally Posted by Faster (Post 869272)
With longish shafts and a sloppy cutlass bearing you can develop 'whip' that would be mainfested as some unusual vibration, most likely only at certain RPMs or beyond certain RPM thresholds. If the rubber is truly gone, then you will get the grinding noise and rapid damage to the shaft and the bearing shell.. don't think it often gets to that stage, though.

I do get a "thumping" vibration at low rpm (try to avoid that), seems to be coming from around the cutlass bearing strut. Prop is relatively clean as I dive it regularly.

DivingOtter 05-10-2012 10:26 AM

Re: Early Cutlass bearing wear. Is this a problem?
 
I have seen that happen with an unbalanced or damaged wheel. People ignoring it till it develops into a larger problem. I tell my customers an unbalanced wheel is like an unbalanced tire. Maybe just a little vibration but over time it will slowly wear out other components.


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