Any risks from putting engine in reverse while sailing?

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eddystone

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I have a Volvo 2002 with fixed prop, straight shaft and Volvo seal. Not sure which position causes least drag when sailing but seems to me letting the prop spin in neutral is probably going to cause wear somewhere. OTOH, does locking it in reverse, which is the only way to stop it spinning (and whining), cause any difficulties to the transmission?
 
I don't know about the Volvo transmission, but Yanmar specifically say not to do it with the gearbox on the GM series.

Pete
 
Some hydraulic gearboxes do not like being spun under sail, something to do with the lubrication cycle being powered by the engine rotating, not the prop. Anyway, the noise is annoying. One is supposed to have either a shaft brake or a feathering prop.
 
If you stick it in reverse and then go sailing you may not be able to get it back into neutral as the cones stick together. This isn't the end of the world as you can start it in gear and then select neutral. We just leave out 2003 in neutral as it causes less drag. The noise is useful in telling how fast you are going.

Worth a read: http://www.catamaransite.com/propeller_drag_test.html
Pete
 
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Our Volvo manual albeit a 2040 says don't put in gear and to run the engine every 10 hours of sailing. If that's not an option fit a shaft brake.

Probably due to wear somewhere.
 
prv said:
I don't know about the Volvo transmission, but Yanmar specifically say not to do it with the gearbox on the GM series.

Pete
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That's interesting, I got a few problems with a Yanmar at the moment.

Cant find a reference in the owners manual or the workshop manual, but I may have missed it!

Do you have a handy reference for that? Ta in advance, CS
 
capnsensible said:
That's interesting, I got a few problems with a Yanmar at the moment.

Cant find a reference in the owners manual or the workshop manual, but I may have missed it!

Do you have a handy reference for that? Ta in advance, CS
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I have been sailing with my GM gearbox in reverse for the past 12 years and this is the first time I have ever heard that it should not be done. Forward gear does nothing, prop still revolves. I start the engine with gear still in reverse, then shift into neutral.
 
I have a Jeanneau 42DS with a Yanmar 4JH4AE engine. Big yellow sticker by the gear/throttle lever stating that I mustn't have it in gear when sailing at 8 knots or more. The text is pretty general and starts with "If this boat is equipped with a fix blades propeller then...." It has been there since new and the English is obviously from a foreign source (e.g. fix blades propeller).

I'm pretty certain that the label was added by Jeanneau as it is in French with the English version underneath. I did check both the Yanmar Service and Operation manuals but failed to find any reference to sailing with lever in or out of gear. I've always followed the instruction as the dealer mentioned it specifically when I took ownership.
 
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vyv_cox said:
I have been sailing with my GM gearbox in reverse for the past 12 years and this is the first time I have ever heard that it should not be done. Forward gear does nothing, prop still revolves. I start the engine with gear still in reverse, then shift into neutral.
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Thanks, the current vibration I got in slow ahead is irritating, looking at all kinds of solutions!

Prop good, shaft good, new cutlass bearing, new driveplate, gearbox flushed and new oil, grr. Putting new engine mounts on tomorrow.....
 
eddystone said:
I have a Volvo 2002 with fixed prop, straight shaft and Volvo seal. Not sure which position causes least drag when sailing but seems to me letting the prop spin in neutral is probably going to cause wear somewhere. OTOH, does locking it in reverse, which is the only way to stop it spinning (and whining), cause any difficulties to the transmission?
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If you read the owners manual for the engine you will find that it advises leaving the gear in neutral if you have a fixed blade prop or in reverse if you have a folding prop.

Like the manual for Jac's 2040 it also advises running the engine for 5 minutes every 10 hours.
 
cliff said:
Or one could stick the shift in forward, that way the wear if any would on the back of the gears.
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You should not do that with ZF/Hurth gearboxes and saildrives, including the ones re-badged by VP on the MD2020D and D1/D2 series, which have stacks of disc clutches not cones. They rely on a mechanical servo mechanism to clamp the discs together. If you put it in forward when sailing the discs will rub together but there will be no servo action to lock them and they will wear. It's recommended to leave in neutral with fixed prop, reverse with folder to make sure it folds.

This probably doesn't apply to the gearbox on the OP's 2002 but as the discussion seems to have spread a bit as usual....
 
It depends upon which gearbox is fitted. From memory, a conventional gearbox with shaft drive does not mind being locked in reverse to stop it rotating. I also believe that Volvo saildrive gearboxes can be put into reverse when sailing.

Yanmar saildives (which are the work of the devil, imho) can not be locked into reverse when sailing to stop the whine. The infamous cone clutches will lock and you'll have to start the engine in gear to free them.

I have a Yanmar SD50 and the 3 blade prop whined worse than SWMBO when underway. A mere additional £2500 for a folding prop solved my problem (with the prop, not my wife, she's far more expensive :))

Always read the manual of the specific gearbox for definitive advice.
 
prv said:
I don't know about the Volvo transmission, but Yanmar specifically say not to do it with the gearbox on the GM series.

Pete
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My Jeanneau manual for a boat with a Yanmar YM series specifically says to put in reverse whilst sailing. Can be difficult to get the gearshift back to neutral sometimes before starting the engine, so often start up with it still set to tickover astern, gearshift moves easily the instant engine starts.
 
davidjackson said:
I have a Yanmar SD50 and the 3 blade prop whined worse than SWMBO when underway. A mere additional £2500 for a folding prop solved my problem (with the prop, not my wife, she's far more expensive.
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Do you have prices for solving the problem of whining wife? Would a folding wife be preferable to a feathering one?
Mine seldom whines but does tend to chatter sometimes. Could this be due to excess lubricant?
 
First all tests say that stopping the prop causes more drag. Second you have to stop the boat to get it out of gear, I wouldn't start it in gear in case something was wrapped around the prop.
 
Yanmar GM sailing in reverse -- a problem or not ?

vyv_cox said:
I have been sailing with my GM gearbox in reverse for the past 12 years and this is the first time I have ever heard that it should not be done. Forward gear does nothing, prop still revolves. I start the engine with gear still in reverse, then shift into neutral.
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Me too and for much longer than 12 years - this comes as quite a surprise - where can we see this advise from Yanmar ?
 
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