Shafts/props not spinning during survey - 02 Jefferson

I was tagging along to a survey and sea trial with a friend of mine interested in a 2002 Jefferson pilothouse. Twin Cummins 450C engines. During survey the surveyor couldn't spin the props at all. Neither would move and inch. Multiple people mentioned they had never seen this.

Theories ranged from fishing line fouling the bearings, the bearings were installed with petroleum jelly so they are all swelled up, to a weird transmission issue that locks the shafts when engines are not running. We splashed it and went on the sea trial and the stb engine was vibrating noticeably more than the port. An obvious physical vibration. Potentially related to the shaft issue on that side.

BUT... both port and stb exhibit the same behavior...no ability to spin freely even when the surveyor went into the engine room and tried with a 2.5' crow bar. This told us that both sides experienced same event or sequence of consequences to get the shafts into this state.

Any ideas or anyone that has seen both shafts completely lock up while not underway? other than the vibration on the stb while underway there isn't anything obvious including the cutlass bearings looking ok.

Thanks in advance!

Could be swelled bearings or bad misalignment. Neither are good. Have it sorted before buying. Both the shaft binding and vibration issue. Should be able to rotate prop shaft by hand at the coupling, worst case rotate with a wrench with minimal effort.

Most likely alignment in my opinion.

Could be the whole drive line needs to be looked at.

In 94 I bought my boat with props that I couldn't turn by hand. 3000 hrs at that point. Invoices in hand showing $$ spend on re-alignment of both engines.
In 2014 the shafts had well over 6000 hrs and still wouldn't turn by hand. I threw $$ at it and since then have been able to turn the props by hand.

If any different, my fuel consumption has gone up a touch??? What effect did the tight shafts have if not to effect fuel consumption?

Yes, the cutless bearings were worn, so eventually I would have needed to change them out, but urgency was not part of the equation.

YMMV

koliver said:

If any different, my fuel consumption has gone up a touch??? What effect did the tight shafts have if not to effect fuel consumption?

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This is a great question and I suppose a follow up. What's the real effect/danger of such a condition? Fuel efficiency yes. But also perhaps further damage to the power train which would cost more to repair down the road?

thanks for the reply...good perspective.

Do not put a pipe wrench on the shafts! You will regret it...

To me the biggest problem is that you don't know what's wrong but it definitely should not be like that. Could be severe misalignment or bent shafts, bent struts or maybe even transmission problems. Running it like that can't be good and likely will do more damage.

Ken

I can't imagine fuel consumption going up after correctly aligning shafts. But stranger things have happened.

The first thing to do would be to break the couplers apart and see if the shafts spin freely after than.

If not then it's time to look elsewhere for the problem.

Severe misalignment wastes fuel, puts stress on the shaft coupler and transmission seals, causes early strut bearing wear, can cause the shafts to wear at the point they ride on the bearings, etc., etc.

How big are the wheels and shafts? I cant turn mine without a wrench, 36" wheel, 2.5" shaft.

Big shafts and props are going to be harder to turn just due to the weight on the bearings. For a 36" wheel and 2.5" shaft a wrench will definitely be needed even with all being right. And yes, no pipe wrenches. Use a wrench on a coupling bolt or use a strap wrench on the shaft.

packing too tight and dried out from lack of use? Big props and shafts can be tough to turn. any easier after the sea trial?

I would also say this sounds like alignment, could ask the yard to detach the coupler from the transmission and see what that shows, also vibration can be caused by alignment, which could be simple or could be bent struts,shafts... If you have two struts per side then alignment is more critical.

When the boat is on the hard the hull distorts some. But it would seem to need to move a tremendous amount to buying the shafts. While on the hard I was able to turn my two inch shafts by pushing on the propeller

What happens if you put a pipe wrench on your shaft? Asking for a friend. [emoji6]

bayview said:

packing too tight and dried out from lack of use? Big props and shafts can be tough to turn. any easier after the sea trial?

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Didn't get easier after the sea trial. Pulled into the slip and the surveyor got a 2.5' crowbar and couldn't move either an inch.

How about seizing, binding clutches?

Only thing to do is have engine and shafts aligned and see what cause is found. Alignment is not a big deal if nothing serious is found.

Mule said:

How about seizing, binding clutches?

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Can happen. But shaft will start rolling as soon as you crank the engine.

My vote is for swollen rubber on the shaft bearings.

Alignment would have to be WAY off to cause that much binding.

Ski in NC said:

Can happen. But shaft will start rolling as soon as you crank the engine.

My vote is for swollen rubber on the shaft bearings.

Alignment would have to be WAY off to cause that much binding.

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I'd agree. Depending on the setup, it may be easily checked by loosening the bearing housing, allowing entire bearing assembly to turn, and then checking ease of rotation.

I take it there was no out of the water part of the survey?

Larry M said:

I take it there was no out of the water part of the survey?

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There was. By the time I got there to tag along they were splashing already. They said the bearings "looked good". I'm leaning towards bearings but best to just get it fixed as a condition of sale. No sense guessing. Get a pro in there and start troubleshooting at the couplers and work back.

I saw this last month on a friends Great Harbor. Twin transmission overhaul after spending on every thing else. Clutch plates binding. Then cleared somewhat after warm up. Predicated by a nut that was to be peened at the factory that loosened up after 10 or so years. So do not count the transmissions out.

tozz said:

Didn't get easier after the sea trial. Pulled into the slip and the surveyor got a 2.5' crowbar and couldn't move either an inch.

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Did your surveyor found anything odd related to this during sea trial (vibration or anything else)?

L.