Turning Prop and shaft

PeteMylett

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When sailing do you guys do anything to stop your props and shafts turning?

I don't currently, but it makes an annoying rumble and I'm a bit worried about causing damage. When I put the engine into gear I still hear a diminished rumble. Maybe putting it into reverse is the answer?

Or, even worse the great expense of a folding prop...
 

Malcb

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As per article in June's YM, you could always try locking the prop shaft with mole grips to stop it spinning and creating drag!!!

The mind boggles at what would happen if you did forget to take them off before starting the engine.
 

Sybarite

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I believe tests have shown that there are advantages and disadvantages of both. For me the simplest is to let it turn.

I tried blocking it in reverse once and it jammed in that position.

John
 

jerryat

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Hi Pete,

Always put mine in astern. I don't fancy the gearbox/bearings/and shaft wearing unnecessarily. Been doing the same for the last 30 odd years and no probs yet.

Cheers Jerry
 

TigaWave

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A word of warning,
after years of using reverse with no problems on several different boats....I did the same on a Volvo sail drive (as folding prop had decided to throw a blade off so had spare fixed blade on) and it locks the gearbox...I thought it was the cable control arm stuck so spent ages dismantling the bloomin pedastol in nice swell hove to, feeling horrible, bits rolling all over the cockpit and trying to escape down the drains.... then that evening read in the small print of the volvo manual, that you shouldn't use reverse to stop the prop spinning! but it should be left in neutral and spinning.
Moral of story...read the gearbox manual if you have one.
 

[2574]

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I've been thinking about this. Yanmar guy says leave it in neutral, the boat owners' manual says put it in astern. I'm confused! The answer has to be a folder next winter!

The Yanmar guy said that some boats will not start (a failsafe) when in gear - and if it locks in astern you then can't start the engine - could be embarassing.
 

aluijten

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I've been told that a normal gearbox (no saildrive) will not lubricate the gears if the engine axis is not spinning. That's why you need to set it in gear to prevent free spinning of the propellor.
As I know nothing about saildrives it might be different there.

Arno
 

VicMallows

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Only bother to put mine in gear if I hear the shaft turning. I then use forward gear; reason being the engine has been known to 'bump-start' .... and I'd rather it did that in the correct direction! (especially as gearbox is chain-drive when astern).

Vic
 

Cornishman

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[ QUOTE ]
When I put the engine into gear I still hear a diminished rumble

[/ QUOTE ]

If your shaft continues to rotate after you have put it into gear it suggests that you have a hydraulic geabox(TMP fitted to many Moody yachts in the 1970s). This will only operate when you have supplied oil pressure to the gearbox from the engine. The mole grip idea is OK, but a more permanent solution is to have a small disc fitted to the shaft and some form of grip which you can screw down on to the disc in the same manner as a disc brake on the car.
 

Sui Generis

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You don't say what engine and gearbox you have, and it does make a difference. Cornishman's answer is the best yet. Volvos will usually stop the prop when you put the gearbox into reverse. If you do that with some Yanmars you have to then start the engine in gear; hydraulic gearboxes are less predictable - no less reliable.

Although a dispute that will run and run, current thoughts are that a stationary prop creates less drag than a spinning one. I don't want to get drawn into either. . .
 

billmacfarlane

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I had a Volvo folding prop and the prop still spun. I always left the engine in reverse gear. I now have a 3 bladed feathering Kiwi prop, and shaft is now stationary while under sail.
 

ytd

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my volvo saildrive (120S-D) manual says the engine shoudl be in reverse if a folding prop is fitted and neutral if a fixed prop is fitted.
 

PeteMylett

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Blimey! Here was I a tad embarrsed about asking such a boring 'newbie' type question.

It seems the answer is keep it in neutral whilst at the same time engage foward and revrs gears..

Seriously though, thank you all for sharing your thoughts. I think I'll get in touch with Mr Volvo and see what he has to say. If I learn anything uselful I'll let you know
 
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