2 distinct lines of oil spray

[fixxxer0]

got this atomic 4 in a C&C 30 i purchased last year. definitely not as well cared for as my previous A4, but I am getting there little by little.


i noticed an oil pad below the engine with some stains on it when i purhcassd the boat, but didn't think it was a deal breaker.

i replaced the pad last week and inspected it today after the engine had a couple hours use to find these two distinct spray marks. (see attached pictures)


what does it look like could be wrong? and what parts do i need to buy to fix it. as you can see there is NO room to work what so ever... cant even see the shaft its so close to the stuffing box. this is going to be a fun one i can tell. (boats in the water already so prolly gonna wait till winter)

[Don Moyer]

These lines of oil are very convincing evidence that oil is finding its way between the tail shaft and the output coupling (probably along the keyway), and collecting between the output and prop shaft couplings. From there, the oil is flung out to where you see it on the rag. The danger of this condition is that it's usually a signal that the shaft (and or the keyway) have developed play, meaning that every time you shift into and out of forward or reverse, the shaft snaps within this play and it will only get worse.

I recommend separating the couplings for an inspection. Perhaps the 1-1/8" retaining nut came loose.

Don

[fixxxer0]

The danger of this condition is that it's usually a signal that the shaft (and or the keyway) have developed play, meaning that every time you shift into and out of forward or reverse, the shaft snaps within this play and it will only get worse.

I recommend separating the couplings for an inspection. Perhaps the 1-1/8" retaining nut came loose.

Don

First, thanks for the quick response as always Don.

You mention the danger of the problem is the play will get worse... what is the worst case situation here? will/can the prop shaft just come loose and go out the backside?

Also, you must forgive my ignorance here... I knew enough to know theres a problem, but thats about it. The boat is in the water right now, would I be able to seperate the couplings (I am assuming its the aft most smaller ring of bolts) without risk of losing the prop and shaft? The other thing is I don't think there is any room to move the coupling if I do get it detched. Any suggestions?

Aside from a loose retaining nut, which I assume would be easy to spot if I can see, how do I inspect the keyway and know if it needs to be replaced?

[Don Moyer]

The worst case situation is that the keyway will shear (lengthwise) and the tail shaft will turn freely within the output coupling. When this happens, the tail shaft is almost always ruined which requires removal of the whole reversing gear assembly to repair or replace.

I can see from your second photo that there is virtually no space between the back of the propeller coupling and the stuffing box, so I don't know how you'll be able to separate the two couplings without moving the engine forward (after removing the three retaining bolts of course). I've never been able to understand how (even quality) boat builders allow this to happen.

Before going to the trouble of moving your engine forward, you might try turning the couplings back and forth (with all the muscle you can muster) with the engine in forward to see if you can feel any play at all between the couplings and the tail shaft. If you can feel no movement at all between the coupling and the shaft, it would remove some of the urgency of the situation, but in my opinion the tail shaft to output coupling connection should be investigated.

To your last question, I see no evidence that the prop shaft is lose in the prop shaft coupling so there's no reasonable threat that the prop shaft will move out the back of the boat.

[thatch]

"ouch"

fixxxer0,
Don points out a very disturbing situation, unless of course you happen to have a fairly long shaftlog hose (not in the picture). If this is the case then shortening it some might give you the clearance needed to split the couplings.
Tom

[fixxxer0]

fixxxer0,
Don points out a very disturbing situation, unless of course you happen to have a fairly long shaftlog hose (not in the picture). If this is the case then shortening it some might give you the clearance needed to split the couplings.
Tom

The length of the shaft hose is about 10" if my memory is correct. I don't know if this is super long or not...

Its a very weird setup and I do not like it much. One end of the hose is clamped to the fiberglass hull where the shaft enters and the other end has one of the stuffing box nuts attached to this homemade aluminum bracket that screws in place to keeps the SB fitting from rotating inside the hose.

I definitely do not feel comfortable messing with this stuff while the boats in the water. I think I may have to just pull the shaft out from the back end and work that way.

PS. my stuffing box never drips, which also makes me nervous. I don't know if the PO put in a dripless packing or something though.

[thatch]

"there's still hope here"

fixxer0,
At 10", your shaftlog hose is about twice as long as usual. Unless there is some overriding circumstance, you should be able to shorten it enough gain the clearance needed to tackle the flange nut and tailshaft seal if necessary.
Sorry to have to end here, i'm off to the airport.
Tom

[sastanley]

fixxxer0,

As Tom pointed out..that is pretty long. I think mine is about 5". I would NOT be doing shaft log & stuffing box repairs in the water (as you well know if you've seen the "Indigo" thread)

Is the nut warm when the prop is spinning? I found that if I had it set to drip about every 15-30 seconds the nut was cool to the touch..if I had it too tight, the nut would get a little warm. If you fix the other issue, you'd have to reset all that anyway.

Some crazy people replace packing & such in the water, which if I knew what I was up against might be feasible..but if you have an issue water would be coming in the boat pretty fast with a torn stuffing box/shaft hose. Then you are paying $$$$ for an after hours/emergency haul out.

You may be able to haul the boat, shorten the hose & move the stuffing box assembly aft to give you enough access. I probably only had about 3" or so of space between the stuffing box nut & coupler, but it was enough to separate & start pressing things apart..I am almost there...
Good luck.

[fixxxer0]

I am gonna go today to look and measure. Maybe 10" is on the long side and my mind is getting carried away...


Eitherway, I just hope it lasts until winter haulout.


I want to try Don's test but I'm not 100% sure what I should be doing. Do I put the engine in forward gear and then try to see if the shaft will turn at all seperate from the coupling? I don't know how i could get the shaft to move since theres no access to it.

[sastanley]

fixxxer0 - there is a nut on the backside of the engine half of the coupler which I assume holds the coupler to the tailshaft. When you separate the two halves it is easily visible. I think Don might be worried yours is lose, and allowing oil to escape thru the seal/tailshaft and then spinning out the coupler.

Here is a pic with mine separated and a socket stuffed in the middle which I was using to push the shaft out. If you follow the arrow, you can just see the retaining nut that the socket is resting on.

Sorry, it is the best pic I have handy of the area in question.

If I understand Don's suggestion, with the engine in gear, if you grabbed a hold of the coupler assembly and shook it/rotated it around, you should be able to feel if the coupler is loose from the tailshaft & the rest of the engine, & possibly because that nut is loose. If everything feels solid, the issue may not be that nut.

[fixxxer0]

Ah thanks for the photo, that clears things up a lot.


Unfortunately, theres no way I can back mine off that far with my current set up.


How hard is it to get the shaft out? To tighten that nut, does the shaft have to be out? Unless maybe you can use an open ended wrench.

[sastanley]

No...just separated..I am performing a different function here (removing the shaft & eventually couplers) but it was a pic which showed the nut. I think Don even gave us the size - 1 1/8". A spanner wrench here may work better..they are thinner..

When I attempted to align my engine/shaft last month, I was able to see the nut with only about 3/4" of separation simply by pulling the propeller coupler (shaft half) away from the output coupling (engine half) - once I got the 'rusty glue' to give way with a putty knife. I see how close yours is...I think that is why Don was recommending the rotate/shake check above, which may reveal whether or not that nut is loose or not. Now that you have this additional picture in your mind, try re-reading post #4..I think it may make more sense.

[wlevin]

Good view

Post #186 in the Indigo thread has a good view of the retaining nut.
Bill and Jeanne
T34C #453
Otter

[sastanley]

new pic

Hi fixxxer0,

I got my prop shaft out and my coupler separated yesterday evening. I took a good pic of the back end of the motor for you with a clear pic of the retaining nut.

Hope this helps, so you can get an idea of how to proceed.

[fixxxer0]

ah nice thanks a lot. a picture says nine hundred and ninety three words.


Being that I have never took anything back there apart it helps a lot to see this angle shot.


I am pretty sure I have a decent line up of work for myself this winter. My engine mounts (C&C style, ie. non flexing) are badly rusted and the vibration is pretty bad since it is mounted on wooden stringers directly on the hull, the cutlass bearing has a little bit of play in it, and I want to get rid of this hose and stuffing box. I figure since all of these things are related I might as well do them all at once, align the engine and be done with it.


I am gonna try and figure out if its possible to put regular engine mounts in there with rubber feet instead of the C&C style mounts, as well as maybe a dripless shaft seal or something similar.