Diag outdrive failure

My out drive started to slip then made a strange noise then stopped working. the electric shift does not go into forward but will go into reverse when idleing on the trailer. . The prop will turn when idleing or in reverse but wont turn with the engine off and the battery disconnected. I tried to drop the lower unit but it wont come loose on the rear... the front of the lower unit will move if I pry on it but the rear wont move any. I removed the torque/exhaust fin and water strainer but I cant find any other bolts to take out... So what am I missing?
Thanks.

Update:

For future searchers...

To remove the lower you have to disconnect the shift wires behind the engine.
With the drive tilted up pull the shift wires through the gimble housing.
Tilt the drive down then unbolt the five bolts on the top of the drive. Be careful the lower unit will fall off if you aren't supporting it.
Now with the lower portion unbolted from the cap. Lower it enough to pull the shift wires through the upper unit.
That's it...
Now take this to a workbench and remove the six bolts by the cavitation fins.
remove the water pickup strainer screw.
remove the exhaust fin and the plate under the fin that the water pump pick up hose is attached too. Just pull the plate away from the housing.
Then you can see the seventh bolt above the water pickup tube. I removed the tube to get to this bolt.
Now the lower will come off the intermediate piece.
Very easy. No need to mess with the pivot caps and seals or mark ball gears!



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Re: Diag outdrive failure

Not sure on the 'lectric shift but there might be a bolt up inside the cavity of the exhaust fin.

Re: Diag outdrive failure

Hi, thanks I cant find any bolts up in the exhaust passage... Any way I did some more checking and found that it will go into reverse but wont go into forward... The prop is still engaged when in neutral. I can turn the prop if I push hard enough, like I am turning the engine over... I don't know what to do at this point. I think it might be the upper gear case? Or can it be something simple like a bad coil or silinoid?
Or does the slipping under load indicate something else?

Re: Diag outdrive failure

7 bolts to take out how many have you taken out a mirror will help

Re: Diag outdrive failure

randy2112 said:

Hi, thanks I cant find any bolts up in the exhaust passage... Any way I did some more checking and found that it will go into reverse but wont go into forward... The prop is still engaged when in neutral. I can turn the prop if I push hard enough, like I am turning the engine over... I don't know what to do at this point. I think it might be the upper gear case? Or can it be something simple like a bad coil or silinoid?
Or does the slipping under load indicate something else?

Click to expand...

There is another post (currently) about slipping under load. Sounds like you have more issues than just that. You cannot turn the engine over with the prop. If you are in gear, with electrical power off, you might get some resistance on the prop because the forward or reverse spring will not be tightly engaged.

I'm not a good 'lectric shift guy so maybe someone else will get you pointed in the right direction. In the end, you are either going to have to study up on it with a good manual, or remove the entire drive and take it to someone who knows what they are doing.

btw, what do you mean re: a "Diag outdrive failure"

Re: Diag outdrive failure

Not counting the exhaust fin bolts I removed the six obvious ones. Where is the seventh bolt?

The manual I have is not very good... What is the best manual for the Electric shift outdrive?

Before the failure the prop turned freely when the boat was off now it wont turn even without power to the coils... Any idea why?

Diag. as in Diagnose..

Thanks for the help.

Re: Diag outdrive failure

On an electric shift OMC, if you're prop won't spin freely when the system isn't energized (or rather, when the engine is turned off and the key is out) ... you may be locked up in your lower unit. What does your lower gear lube look like?

Re: Diag outdrive failure

southkogs said:

On an electric shift OMC, if you're prop won't spin freely when the system isn't energized (or rather, when the engine is turned off and the key is out) ... you may be locked up in your lower unit. What does your lower gear lube look like?

Click to expand...

The oil is dark but no signs of water or metal.
The prop turns at idle and in reverse . but it only shifts when going into reverse.
I can get the prop to turn by hand but it is very hard and it feels like turning a car engine over by hand...

Re: Diag outdrive failure

randy2112 said:

...I can get the prop to turn by hand but it is very hard and it feels like turning a car engine over by hand...

Click to expand...

That's what ain't right (at least as I understand things). What happens if you disconnect the shift wires in front of the intermediate housing?

With the outdrive removed, the engine running should run smooth and easy. Separated from the lower, the upper gearcase should turn by hand (might be difficult, but it should turn - the gears don't "engage," per se). The lower separated from everything else on an electric shift, the propeller should spin with your 4 year old using their pinky finger.

What does your upper gear lube look like?

Re: Diag outdrive failure

Can someone tell me where the seventh bolt for the lower unit is located?

The engine idles and revs just like it always has...

I have a battery cutoff switch and even with the batteries disconnected it still does the same thing.

As for the upper oil I will be looking at it this afternoon (Pacific time).

Thanks for the help!

One more ? What is the gear ratio for a v6 vs a v8 out drive?
Apparently I have a short shaft v8 grive witch is supposedly hard to find. 33" from the top of the power head to the bottom of the Scagg.

Re: Diag outdrive failure

You don't really remove the lower unit. You take the "lid" off the top of the drive and lift the upper gearcase out (like delivering a baby c-section). Watch the shift cable or wires (umbilical).
Then you'll be left with the lower with the exhaust housing attached to it. No reason to remove the exhaust housing from the lower really, but it'll be obvious if you do need to unbolt it.

Re: Diag outdrive failure

I ordered a better manual and am waiting for it... I also am having a shop look at it just to see what they say. I will post back in a couple of days
Any other comments are welcome since I have more time than money! LOL
If some of my ? seem kind of stupid... I am blind and don't see things that may seem obvious to sighted people. And the peple that are my eyes are not always mechanically inclined...
Thanks for the help.

Re: Diag outdrive failure

randy2112 said:

... I am blind and don't see things that may seem obvious to sighted people...

Click to expand...

Don't sweat it. I have two good workin' eyes and have asked dumber questions. Let's see what the shop tells ya'.

BTW - you may want to start shopping for a new (used) stern drive. Sometimes with these things, if you're patient and keep your eyes peeled, between donor boats and the internet you can find a working stern drive cheaper than you can repair the one you have.

Re: Diag outdrive failure

southkogs said:

Don't sweat it. I have two good workin' eyes and have asked dumber questions. Let's see what the shop tells ya'.

BTW - you may want to start shopping for a new (used) stern drive. Sometimes with these things, if you're patient and keep your eyes peeled, between donor boats and the internet you can find a working stern drive cheaper than you can repair the one you have.

Click to expand...

LOL Thanks... I am looking for one. I have a line on a drive that is in excellent condition, is 700.00 reasonable for a good working drive that has been well maintained?

Re: Diag outdrive failure

randy2112 said:

...is 700.00 reasonable for a good working drive that has been well maintained?

Click to expand...

Tough question to answer well.

You can find remanufactured lower units for Mechanical Stringers for $3k. Rolling the dice on a used, but "in good condition" drive for $700 looks like a good buy against that ... but you can be frustrated later if that $700 drive fails after only a few hours of use.

You just can't get past the fact that it's a risk. Especially when you're dealing with old obsolete boats.

I found a complete Electric Shift Drive, 165HP just like I needed for $400. Bought it flat out without even really testing it. I decided to gamble. It paid off. I've been running on that drive for a couple of years while working on rebuilding a backup drive (not really getting that far on that part ). I thought $400 was cheap compared to what I had been seeing, so I decided I could afford the risk.

$700 is in the ballpark. If you're gettin' a "good vibe" from it (or better yet can test and confirm it works), and you can deal with the risk factor, then it's not a bad price for a complete drive.

Re: Diag outdrive failure

southkogs said:

Tough question to answer well.

You can find remanufactured lower units for Mechanical Stringers for $3k. Rolling the dice on a used, but "in good condition" drive for $700 looks like a good buy against that ... but you can be frustrated later if that $700 drive fails after only a few hours of use.

You just can't get past the fact that it's a risk. Especially when you're dealing with old obsolete boats.

I found a complete Electric Shift Drive, 165HP just like I needed for $400. Bought it flat out without even really testing it. I decided to gamble. It paid off. I've been running on that drive for a couple of years while working on rebuilding a backup drive (not really getting that far on that part ). I thought $400 was cheap compared to what I had been seeing, so I decided I could afford the risk.

$700 is in the ballpark. If you're gettin' a "good vibe" from it (or better yet can test and confirm it works), and you can deal with the risk factor, then it's not a bad price for a complete drive.

Click to expand...

It has a 2 week garrenty... shipping is outrageous though. If I had to return it I would be out 400.00...

The shop I took it to said the electrical part of the shift system back to the actual drive is all good. The lower unit is bad for sure and it is stuck in forward gear. Can this just be because of the lower unit?

Re: Diag outdrive failure

randy2112 said:

...The lower unit is bad for sure and it is stuck in forward gear. Can this just be because of the lower unit?

Click to expand...

Boom or Howard might have another thought, but that makes sense to me. Really, between the throttle and the lower unit all you have it a couple wires to run voltage through. It's not until you get into the lower that you have things mechanically happening (for the most part). So, it makes sense that the lower is bad.

I've not cracked a lower open on one of these. I don't know if there are any special tools required. Do you have a way to get a vibe on the project through a manual or anything?

Re: Diag outdrive failure

southkogs said:

Boom or Howard might have another thought, but that makes sense to me. Really, between the throttle and the lower unit all you have it a couple wires to run voltage through. It's not until you get into the lower that you have things mechanically happening (for the most part). So, it makes sense that the lower is bad.

I've not cracked a lower open on one of these. I don't know if there are any special tools required. Do you have a way to get a vibe on the project through a manual or anything?

Click to expand...

I have a Selloc manual on the way, It will be here Monday. Then I will start tearing it down and see what is going on with the Lower unit.
Just so I am clear on a couple of items: The shifting occurs in the lower unit. The upper is just the drive gear and shift coils correct?
To remove the lower I have to remove the upper unit then I can get to the bolts that hold the lower unit to the rest of the outdrive?
Removing the upper unit is just a matter of removeing the six bolts by the cavitation fins and then lifting the upper off?

Thanks again for all the help.
Or do I need to remove the whole outdrive then separate the two units?

Re: Diag outdrive failure

On an electric shift: I'd take the whole drive off and then take the upper and lower apart. You don't necessarily have to, but I think it's the better way.

The lower has the shift coils and all the shifting happens down there. The upper is always spinning ... even in neutral.

Once you remove the drive from the boat (make sure you disconnect the shift wires), remove the top cap of the drive: 5 bolts around the perimeter. Once you remove that cap, you can lift the upper gear case right off the lower (mind the shift cables). The exhaust cover can be unbolted from the lower (that's the six bolts you mention), but you don't necessarily need to do that.

Re: Diag outdrive failure

Thanks, I understand how it works now. My manual will be here Monday and I will have someone here to read it and help with the visual stuff.
Thanks again.