Topic: Prop Shaft Dilemma
The two scrooz in the flange are commonly cross drilled for lock wires. After torquing to 35-40 Ft lbs the lock wires are added. It's S.O.P.
Re: Prop Shaft Dilemma
Mine were crosswired and yet it happened. I even sank 2 holes in the shaft so they had something to catch on. Yet it happened.
I tightened them to the max, yet...
Maybe they don't go all the way down the thread?
Re: Prop Shaft Dilemma
What's S.O.P. by the way?
Re: Prop Shaft Dilemma
Standard Operating Procedure...
Shaft Brake. No engine at all. Two bladed prop, a reference mark on the shaft, access hatch in the cockpit and you line up the prop in the lee of the keel.
Re: Prop Shaft Dilemma
Could redrill the flange and shaft together, tap and thru bolt them. But most people wouldn't uncouple it every year and add some more c5a, and then you'd never get the thing apart.
Re: Prop Shaft Dilemma
Guys,
what on earth can be done about the prop shaft wanting to slip out of the boat and mess up everything?
During this trip from Halifax to Bermuda this summer, the propeller turned for about 1300 miles while sailing so one sunny day I hear a squeaking sound from the bilge. As I need to lay down every time I exert my intellect, I went into my bunk and pondered on the source of that disturbing sound. Seconds later I pictured the stainless steel clamp I put on the shaft (as a safety against such mishaps), carving into the nut of the packing gland (sorry if the lingo is not right here).
I quickly jumped in the cockpit, opened the access hatch et voila,
the shaft is only milimetres from leaving the flange, with the key precariously hanging above a deep bilge, and the clamp eating away at the bronze nut of the packing gland.
I find the 2 screws in the flange that are supposed to hold the shaft are a joke. The twisting force of the propeller through the water when covering such distances is too much for them.
For the rest of the voyage I locked the prop in reverse and thus lost 0,5 knots (12 miles per 24h!) of precious boat speed. Even so, we did 800 miles in 8 days which is not so bad for this little boat.
Any ideas how to make a more serious safety system for this potentially dangerous problem?
Re: Prop Shaft Dilemma
So, now that Christian is selling his boat....Christian, did you just duct tape it up for the new owner......KIDDING! ;D
I have a Manecraft dripless shaft gland, but still need something to hold it it all into the boat, I use a zinc forward of the manecraft seal so the shaft can't possibly slide off.
Question: if you are running your boat out of the water (I have a fresh water flush, so no trouble with cooling...do you figure the prop shaft at the cutless bearing should have some lubrication while running engine on the hard?! I was running it the other day, had it in gear (to charge batteries- my Farymann aftermarket alternator requires engine in gear to charge) I herad a skronky kind of whine for a few seconds, thought it was dry shaft turning in dry bearing?! I almost had heart failure...took several minutes to stop the frantic pulse, as I thought something terrible had happened! But all seems ok...I will have a hose outside too to wet prop...thoughts?! Good lord, who needs aerobics, I have a boat! ;O
“You get a boat for only one reason, because you want one. If you’re worried about being practical, forget boats.”
Re: Prop Shaft Dilemma
Shannon,
I'm not 100% sure about this but I don't think it's a good idea to run your engine in gear out of the water for more than a minute or so. Why don't you buy a cheap battery charger and plug it in the 110 outlet at the marina? To run your engine in gear for an hour or two is asking for trouble. You can damage your transmission, cutless bearing, shaft...I'd think so....anybody out there can confirm or demolish this statement?
- Adrian
- Administrator
- Offline
Re: Prop Shaft Dilemma
I would be a little relucant to run my engine in gear out of water too. I'm not sure what sort of lubrication the water would provide, but I am willing to bet it would do a lot of cooling.
Re: Prop Shaft Dilemma
Well, I do have freshwater circulating through the engine, so it is being cooled properly, (exhaust water normal) and I did only run it for a few minutes, however, I do agree (and came to the conclusion quite quickly!) that of course the prop shaft outside the boat likely wants the water lubricating ie: cooling the cutlass bearing. Because, I figured, I have the proper cooling water, and oils, so the engine inside the boat is exactly the same, in our out of the water....the only difference would be, of course, no water around outside of boat while she is out of the water....so I am assuming the short lived skronk sound was the cutlass bearing/prop shaft entry heating up....I took it out of gear immediately...the sound stopped, and I turned off the engine right away...so, this dope learned a lesson, and hey, at least I learn FAST from my lessons!
Thank you for politely telling me how stupid I was!
“You get a boat for only one reason, because you want one. If you’re worried about being practical, forget boats.”
Re: Prop Shaft Dilemma
"The lubrication for a cutless bearing is seawater, which is a fair lubricant but not a great one."
(as per "Heavy Metal" article in Cruising World"...
ooops...I'll keep everyone posted on what may or may not have transpired! Hopefully not much, but I'll prepare for the worst....eeeeediot!!!
Luckily the boat is out of the water for at least a few more months so I have no time issue, thank heavens!
“You get a boat for only one reason, because you want one. If you’re worried about being practical, forget boats.”
12 2006-02-24 06:27:52 (edited by Bill NH 2006-02-24 06:28:59)
Re: Prop Shaft Dilemma
In addition to the cutless bearing cooling issue, it's generally not good to run a diesel without a load on it for long periods of time. Letting a diesel run without a load keeps it from reaching its design operating temperature, resulting in incomplete combustion and carbon buildup. A prop spinning in air isn't much of a load... This is why, for example, one should put the engine in gear while charging your batteries under sail rather that just running it in neutral while sailing. And if you do idle an engine for a while, it's good to load it up to blow off the buildup before shutting it down...