Thoughts on causes of 'cluncky' propellor please

Stooriefit

Active member
Joined
30 Jan 2007
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197
Hi folks,

over the past few weeks my propellor has developed a 'clunckiness' which it didn't have at the start of the season. I'm assuming this is caused by vibration and my questions are

-what might be the cause of the vibration? I haven't been aware of hitting anything which might have damaged the prop.
-am I likely to do more harm by leaving this until the winter haul out to resolve?

The boat is a Victoria 34 with a three bladed prop turned by a Yanmar 3GM30F. The cutlass bearing was replaced in 2009.

Thoughts welcome!
 

ribrage

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25 Jun 2006
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Passed the monkeys - heading East
First things first - take a swim ,make sure the prop nut is tight !

After that - might be movement on the keyway in the shaft, the longer you leave it , the more the wear on the shaft and as always the bigger the potential bill.
 

yotter

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3 Aug 2007
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Me Inverkip, boat Kip in winter, Craobh in summer
Hi folks,

over the past few weeks my propellor has developed a 'clunckiness' which it didn't have at the start of the season. I'm assuming this is caused by vibration and my questions are

-what might be the cause of the vibration? I haven't been aware of hitting anything which might have damaged the prop.
-am I likely to do more harm by leaving this until the winter haul out to resolve?

The boat is a Victoria 34 with a three bladed prop turned by a Yanmar 3GM30F. The cutlass bearing was replaced in 2009.

Thoughts welcome!

Loose shaft anode?
 

Rigger

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17 Jan 2004
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354
Location
N Wales
Possibly something fouling it?,bit of rope/netting/ plastic bag etc. Does it happen at all revs and in reverse?
 

TQA

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20 Feb 2005
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Carribbean currently Grenada
URGENT

Check your coupling between shaft and gearbox. It may be loose or failing in some way. If it fails completely it can be nasty but partial failures allowing the shaft to flail can be catastrophic as you can have large holes where stern tube and or P bracket used to be.

I have just acted as starboard engine to move a large yacht to the boatyard because they need to remove a badly bent shaft. A partially failed coupling did the bending at tickover in a couple of seconds.
 

saxondale

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15 Sep 2008
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Hamble
I had similar and it turned out to be a piece of packing from the prop shaft arm (I'm sure it has a technical name) had worked loose. sorted it with a couple of jubilee clips to stop further slippage after using a drying berth. took 5 minutes to rectify. hope yours is as simple.
 

PurpleKate

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6 Jan 2009
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Location
Solent
I had this issue and the cause was the shaft anode had lost one of its bolts so was just hanging on and rattling on each turn
 
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South Oxon Boatat Wicormarine
I had a noise that started and gradually got noisier over several hours turned out to be rear engine mount adjuster bolt come loose and engine had dropped by 5 mm on one corner. Worth checking all mountings.
 

Stooriefit

Active member
Joined
30 Jan 2007
Messages
197
Thanks for those thoughts. There isn't a P bracket or shaft anode on the V34 as the shaft is short and exits into an aperture in the keel. I've had look at the pop from the pontoon and everything looks to be in order. Might be the engine mount which hadn't crossed my mind.
 

Stooriefit

Active member
Joined
30 Jan 2007
Messages
197
Is there a rope cutter? If so, something may be amiss with it. Happened to me.

Yes I do have a rope cutter. It seemed to be all tightly secure at launch back in March but I guess that is possible. Thanks. I think I'll need to get an engineer out to have a look whilst I'm still in the water.
 

Aardee

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22 Jan 2004
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2,979
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Portsmouth
I had similar and it turned out to be a piece of packing from the prop shaft arm (I'm sure it has a technical name) had worked loose. sorted it with a couple of jubilee clips to stop further slippage after using a drying berth. took 5 minutes to rectify. hope yours is as simple.

I think you're referring to the Cutlass Bearing, which would have been my suggestion too.
 

Bobc

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20 Jan 2011
Messages
9,879
Dry it out against a wall PDQ and have a look at it. It might be nothing serious, but better to know what it is as soon as poss.
 
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