afraid of Very Bad things/merc outdrive

nola mike · Nov 6, 2009

so, i'm out for thr last ride of the year, and decide to run wide open. everything's fine, then the boat loses power as the engine revs. i immediately shut down, and when i restart, it won't go into gear. shift cable is smooth, but nothing happens; no grinding, nothing. strange thing is is that with the engine off, the prop locks going into forward, but not reverse. when i get home (huge ordeal) and get on muffs i'm not getting any raw water exhaust. so i shut back down. planning on pulling the drive next week, any idea of what i'm looking at?

ErieRon · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

I'm going with engine coupler. It would explain not going into gear and revving, and no water flow. The drive shaft in the lower end has to be turning to turn the water pump impeller. That's turned by the coupler shaft, which engages in the engine coupler. If it were u-joints, gears etc., I would think you would be hearing some noise. If it were just the shift cable, the impeller would be turning. Take a flashlight and mirror and look low behind the engine where the coupler shaft goes into the coupler from the drive. Look for metal shavings, rubber, debris.

Just my opinion...others will chime in.

searay3 · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

Could also be the upper gears. Take off the top and have a look. Could also be the input shaft to the lower. (shaft between the upper and lower). Check oil condition and remember the upper and lower share oil. On the bright side, if it is the drive, SEI doesn't break the bank...

FreeBeeTony · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

I would bet it's the top of the drive shaft on the lower unit........

jollymon · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

Sounds alot like what happened to me last summer. Three days before a 10 day cruise. I also feared it was the coupler, but it was the upper half of the outdrive.

I was lucky, A friend had a spare, and my mechanic was quick, boat was out of commision for 48 hours!

Fishermark · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

FreeBeeTony said:
I would bet it's the top of the drive shaft on the lower unit........

Here's a picture of what THAT looks like: (It's what happened to mine. Could be your coupler... but the only way to be sure to is look).

Bondo · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

FreeBeeTony said:
I would bet it's the top of the drive shaft on the lower unit........

Ayuh,.... If it's an Alpha 1 or earlier, I agree.... Right at the oring groove...

Something is Broken,... Drain the case,+ Look for Metal....
Pull the drive,+ Split the cases... If the Problem hasn't Jumped out at you by then, pop the top cover...

nola mike · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

Bond-o said:
Ayuh,.... If it's an Alpha 1 or earlier, I agree.... Right at the oring groove...

yes, it's an alpha 1

Bond-o said:
Something is Broken,... Drain the case,+ Look for Metal....
Pull the drive,+ Split the cases... If the Problem hasn't Jumped out at you by then, pop the top cover...

will do. i guess it could be worse. looks like with application of enough time (i have the winter) and money (well, i own a boat, so no choice), this isn't TOO bad. which parts exactly are you talking about though? looking at the stern drive manual, page 3A-10, are the gears in question somewhere about part # 6-8? and the "engine coupler" is #37?

lastly, can i fog the engine and otherwise winterize the boat with the stern drive off? obviously, i won't run it long enough to get hot...

myoldboat2 · Nov 6, 2009

Re: afraid of Very Bad things/merc outdrive

i can see behind my engine where the splined u joint shaft enters the coupler. with a flashlight i could see that the coupler was turning but the shaft was mostly not turning. coupler was shot.

Bondo · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

lastly, can i fog the engine and otherwise winterize the boat with the stern drive off? obviously, i won't run it long enough to get hot...

Ayuh,... Sure....
Just Drain the block,+ manifold....
Then pull the sparkplugs,+ squirt oil into the cylinders....
No reason what so ever to Start it....

Btw,...
The Coupler is bolted to the crankshaft/ flywheel,+ the gears We're talkin' about are the Upper gear set....

Bt Doctur · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

Fish, that shaft would give a whine ,not stop the water or shifting.
Remove the drive and use a hose in the water inlet hole

Fishermark · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

Bt Doctur said:
Fish, that shaft would give a whine ,not stop the water or shifting.

Are you talking about the picture I posted?

Because that would definitely stop both the water pump AND the shifting / movement of the boat.

If you are not referring to the picture I posted, then forget my reply as I'm not sure what you are saying.

Bt Doctur · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

Nope, the upper gear set would still spin with that shaft in place, would make some noise, but would still spin.

ziggy · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

i think i understand what bd is saying.

the pic looks to be the upper drive shaft located in the upper housing. the driven gear would still be in mesh with the drive gear. i could believe noisey as the broke part of the shaft isn't turning or supporting the driven gear which would be wanting to come out of mesh since it's no longer supported top and bottom. assuming them too gears stay in mesh to some degree, the upper drive shaft driven gear would still be splined to and turning the drive shaft in the lower which would be driving the impeller... shifting would still occur since everything would still be turning.

i see no o ring on that shaft. i assume the oring groove being mentioned is the drive shaft in the lower. which from what i get is a very possible place for it to break if you have the groove. a break there would stop the water pump and no shifting because there's no connection between the broke part of the lower drive shaft which drives the prop shaft... you'd still be shifting, just nothing to drive the shift...

that's the way i understand it...

feel free to correct me.....

Fishermark · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

ziggy said:
the pic looks to be the upper drive shaft located in the upper housing. the driven gear would still be in mesh with the drive gear. ... shifting would still occur since everything would still be turning.

Okay. Yep - I see what you are both saying. And yes, I guess that is right. It's been long enough that I had to go back and see from my own notes what happened to me. In my instance I had two failures - the break you see in the pics above, and the stripping out of the top of the lower drive shaft where it enters the upper drive shaft. (Is that as clear as mud?

)

Anyway, that break resulted in the same type of symptoms the original poster describes. Here is where I write up what happened to me:

Broken Driveshaft

ziggy · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

and the stripping out of the top of the lower drive shaft where it enters the upper drive shaft. (Is that as clear as mud? )

nope, to me that's very clear if i'm thinking right. your driven gear would still turn the broke shaft, but since there were no splines on the drive shaft in the lower, the upper drive shaft would have nothing to drive... overheat and apparent no shift condition...

bummer, two failures in one foul swoop..... bet that was expensive...

Fishermark · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

ziggy said:
bet that was expensive...

Just a new drive.

But truthfully - a brand new Sterndrive Engineering drive is a great deal. I sold that boat about six months ago, but never had any drive issues the in four or five years I used the aftermarket drive. (Other than paint and corrossion issues - which I understand they addressed with later models).

nola mike · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

ok, after looking at some diagrams and these posts, i think i see what everyone is talking about. maybe.
so, if it's the upper gearset by itself, that shouldn't cause my symptoms, right?
we're talking about the longer lower drive shaft that appears to sit in the upper gearset, correct? a failure of that shaft appears to be able to cause my symptoms. looks like that is a significantly more involved repair?

if anyone has a good diagram of what we're talking about, i'd appreciate it..

Bt Doctur · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

In the Adults section , manual #6 I think.

ErieRon · Nov 7, 2009

Re: afraid of Very Bad things/merc outdrive

Go here and download this manual;

http://www.4shared.com/file/115650149/5fc7e090/Service_Manual_06.html

It will show you what you need.

afraid of Very Bad things/merc outdrive

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