Reprise: What to do with trans while sailing

[higgs]

removehtml]We have had this discussion before so when I read Don Casey on this topic in Feb Sail mag, I thought I'd put it out there.Casey says not to leave the trans in nuetral for an all day sail, as the shaft, while turning, will not be getting the proper lubrication if the engine is off, thus putting wear on the bearings.  Error: Error: expected [/URL], but found [/removehtml] instead[/removehtml]

 

[Don]

Does it really matter very much either way?

For all the discussion, debate and contrary opinions expressed previously, I can't help but think it is largely irrelevent. Unless one is cruising for days/weeks/months on end, the shaft will free wheel if left in neutral quite slowly compared with it's speed under power making tha actual wear insignificant. When one considers the effect on speed under sail, I can't help but believe anyone who really cares would have a folding/feathering prop so this argument also seems fundamantally challenged.Maybe it's the seasonal effect which makes us ponder such things...

 

[Ross]

I should think that it may depend upon the transmission.

There have been times over the years when similar statements were made concerning cars with automatic transmissions. That they shouldn't be towed on their back wheels if the engine wasn't running.(rear wheel drive) I don't know that there is an oil pump in the gear box, just the gears turning and splashing oil around. I know on my Volvo transmission that the gear case is at least half full of oil so the bearings front and rear are running in oil although not completely submerged.

 

[Maine Sail]

What's the engine

Depends on engine and transmission. What do you have?That's like as asking.. "How big of a truck do I need to tow my boat?"More info is always good because not all transmissions are the same...

 

[higgs]

What I know

I know Don Casey knows his stuff.I also know that when any metal part is moving against a stationary metal part, friction, thus wear, is taking place.

 

[Ross]

How long is a rope? How heavy an anchor do I need?

Will this snatch block be big enough for my boat? You mean questions like that , Maine Sail ?

 

[Ross]

Higgs, Bearings in transmissions are all

ball and roller and they all run in oil. There is practically zero friction in these situations. The greatest wear areas will be on the tooth faces on the gears. Even then with just the least amount of oil you won't get metal to metal contact. That oil film will always be there. Now if you cleaned the gear case with gasoline and reinstalled it dry then it would suffer greatly.

 

[ed]

yanmar says leave it in gear

So that is what i do.

 

[Ross]

You have two choices, in gear or in neutral

pick one, the safe one is in gear...........nothing is turning, the second choice is neutral the shaft turns . How long before you have a problem? Who knows! Did you keep it in gear ? No! Well that's the problem. Is it ? Who can tell? Only if you set up a transmission and drive the propeller shaft for several hundred hours at relatively low speed will you ever be able to say . And that will be only one transmission out of how many? Thousands? So a boat owner asks" do I sail with the tranny in gear or in neutral. Conference table discussion, result "say in gear". Why? Why not? One is as good as the other. Someone needs to explain what the running engine changes inside the gear case.

 

[John]

Universal manual

The manual for my Universal M35-B says to leave it in neutral or reverse, but not to leave it in forward.

 

[Ross]

John, Do they say why?

If nothing moves why would it matter?

 

[John]

Nope

No, they don't say why. I assume that the prop shouldn't drive the transmission and engine, which theoretically is what could happen if it's left in forward I suppose. Maybe the fact that the torque would be reversed has something to do with it (although I would guess the torque would be the same as when the engine is running and the tranny is in reverse).

 

[Ross]

I tend to think that these instructions are

arbitrary. There isn't enough power in the prop at 6 knots the crank the engine. Further, cranking it in the normal direction of rotation wouldn't be harmful where as cranking it backwards might be harmful.

 

[Benny]

I suspect the transmission will be subject to wear

either way. With the transmission in gear the prop will try to turn the shaft inducing a stress force in the gears and the clutches. In both cases the wear should be insignificant so perhaps this argument will be only relevant to those who race. A folding prop or a shaft lock would be other alternatives.

 

[Stu Jackson]

Reprise: oh NO, not AGAIN

Maine Sail has it right - it depends on your transmission.Read the instructions that came with it.

 

[Ross]

I know that my transmission is rated for my 10 HP engine but also for a 20 and

30 HP engine. There is no mention of in gear or not in my manuals but that doesn't mean anything with regard to other manufacturers

 

[Don]

for Yanmar engines/trannys

"the shaft should not be locked via reverse and that this could cause damage...they advised installing a $1400 shaft locking mechanism"This above quote is Yanmar's recommendation regarding locking prop shafts while sailing.ps. must be a gold plated shaft lock

 

[Ross]

Want a good reason to avoid a Yanmar Transmission?

;D

 

[ITMaster]

Don, I am not sure why you say what you do but,,,,,

Perhaps, could you please explain why Yanmar would say not to lock the tranny in reverse and why Catalina would tell us to do exactly that. I spoke with Warren Pandy, the plant manager at the Largo plant about this very issue and he specifically told me that for our 387, hull # 24, with a 40 hp 3JH3E engine and sail drive, that we were supposed to lock the tranny in reverse when sailing. Why do you suppose that the plant that makes the boat would tell us something that is the opposite of what you say Yanmar indicates we should do?I have noticed that the shaft turning, without the engine running, that there is no water being pumped to the bearing assembly and the graphite at the seal gland to cool these parts that are turning without the tranny locked in reverse. How is the part lubricated or cooled with it turning?I'm not trying to be argumentative, just trying to understand why you state something that is the exact opposite of what the manufacturer would tell me to do and perhaps try to understand whom I should consider the credible authority on the subject.Help me understand this disparity please Sir.

 

[Rich (P303)]

Lock...

transmission with a shaft lock. If no shaft lock... engage in reverse, as on mooring.