transmission

Re: transmission

feeds@yuku.com (nickwigen) — Tue, 29 Apr 2008 06:02:50 GMT

Gene: I think we saw the same letter about airplanes and I totally agree with your observation about drag, old wives tales, etc. My experience with free-wheeling vs. locking is the same as yours with a bit of speed increase when we let it spin. We resolved the issue about 4 yrs ago with a feathering prop.

I think the locked prop causes a lot more turbulence. The biggest thing I noticed with our 1990 boat (stubby barn door rudder) was how much more effective the rudder was with...

Re: transmission

feeds@yuku.com (yorkrose) — Mon, 28 Apr 2008 16:50:30 GMT

I would not worry at all about extra wear on the transmission due to shaft rotation while sailing. There are virtually no forces involved, other than a bit on the thrust bearing. The transmission parts run on roller bearings and are well oiled. They should last for many years under a condition of free-wheeling.

I agree with the noise comments. In my view that is the only thing to be considered. We initially placed the transmission in reverse, like the conventional recommendation,...

Re: transmission

feeds@yuku.com (pwinterfeld) — Sat, 26 Apr 2008 05:38:38 GMT

I have been sailing for years with the transmission in neutral (on several different boats including 2 Catalinas) The discussion on whether to leave the transmission in neutral or reverse has gone on for so many years. There are good reasons for each setting but the vibration more than the noise has always bothered me - has anyone installed a brake for the shaft ??? I have seen the advertisement for such a device in many magazines. Yes, I know its another thing to remember when starting the...

Re: transmission

feeds@yuku.com (tomcharron2) — Fri, 25 Apr 2008 09:00:25 GMT

In answer to "why not place transmission in Forward while sailing?"...

The Prop shaft (with engine off) while sailing (either in NEUTRAL or FORWARD) ROTATES CONTINUALLY...at least on my C42 MiVida #631. This rotation is fairly noisy too....not so nice when sailing expecially when down below. And contributes to continual wear on transmission etc.

When the transmission is placed in REVERSE while sailing all prop/shaft rotation stops as the prop is pulled thru the...

Re: transmission

feeds@yuku.com (nickwigen) — Thu, 24 Apr 2008 18:38:45 GMT

In forward the prop will continue to turn with the transmission pressure plates dragging. The mechanical configuration is such that as the torque increases the plate pressure increases. In reverse the torque is in the correct direction to increase the pressure. In forward they will drag. The torque delivered by the stalled prop is not enough to turn the engine. Until we installed a feathering prop we used the method Tom Charron describes.

Re: transmission

feeds@yuku.com (Sandy Golden) — Thu, 24 Apr 2008 11:49:13 GMT

I called my Yanmar mechanic Pacwest in San Diego. They are very experienced Yanmar shop. Was told that Yanmar has put out a service advisory that when sailing and engine is shutdown, it must be left in neutral or the warranty on the transmission will be voided if a problem develops. Was told this advice probably was to protect Yanmar from liability if your prop hits something while in reverse when engine is off and there may have been one problem recently. Was also told...

Re: transmission

feeds@yuku.com (tomca) — Thu, 24 Apr 2008 08:39:59 GMT

With my Flex O Fold propeller I always sail with the transmission in reverse to get the prop to fold properly. I have been doing this for 4 yrs now without a problem. On my previous boat, a Catalina 38, I also sailed with the transmission in reverse to stop the shaft from spinning and allow the propeller to fold correctly. I feel the wear on the transmission from constent spinning is worse then having the gears lock in place and hold the shaft. Now I understand that with a folding propeller...

Re: transmission

feeds@yuku.com (seaair) — Thu, 24 Apr 2008 07:51:23 GMT

Why put the transmission in reverse? Why not forward?

Unless I am totally turned around (which is quite possible), putting the transmission in reverse will try to turn the engine backwards, which could lead to all sorts of problems. If it is in forward, it will try to turn it in the usual direction, and it would be easier on the system to start while under sail. In either case, there is not enough force on the prop to actually turn the engine.

I am confused.

Re: transmission

feeds@yuku.com (tomcharron2) — Wed, 23 Apr 2008 20:48:39 GMT

This has worked for all the 9+yrs I had the Catalina 3 Bladed Stock prop in place.
Stops auto prop rotation (quite noisy when sailing in neutral).
Never had problems with tranmission following this procedure.

Procedure was/is:

1.) Set sails

2.) Kill engine (if not already done before setting sails)

3.) Put Transmission in REVERSE to stop auto rotation

4.) Always Start engine if needed for power WHILE TRANSMISSION IS STILL IN...

Re: transmission

feeds@yuku.com (sashay567) — Wed, 23 Apr 2008 14:01:28 GMT

Yep, that is what Yanmar recommends. The reason they use is that it may jam the clutch cone. FWIW, because I have an autoprop, I have to put mine into forward to get the prop to feather (long technical explanation why). Dave Swain over at Yanmarhelp.com says that while Yanmar's recommendation really applies to fixed props, there is little chance of damage if you have a feathering or folding prop.

I think there has been discussion in the past where people sailing with the...

transmission

feeds@yuku.com (Izablue2) — Wed, 23 Apr 2008 10:09:42 GMT

I just got a e-mail from H&S yachts(where we bought the boat) that Yanmar recommends that when the boat is sailed, the tramsission is to remain in neutral. Yanmar states that their warranty will be void if don otherwise.

I always ran mine in reverse!

Any thoughts out there?

Mark

Izablue 835/3