Outdrive quit while crusing

[jim9601]

I was out on my boat and cruising at about 1/2 throttle when my out drive quit driving, it will not engage the prop in any gear. Does anyone have any ideas as to the possible causes? I'm hoping that it may be something simple. Its an Alpha One Mercruiser with a 350 engine. Thanks, Jim

 

[ktbarrentine]

Re: Outdrive quit while crusing

Do any recent maintenance on the drive? Can you take a look under the bell housing (with a mirror) to see the shift shaft engagement? I am sure you will get a good troubleshooting plan on here.

 

[tpenfield]

Re: Outdrive quit while crusing

Could be spin prop hub . . . Check it out to see if it spins independent of the drive shaft.

 

[Bondo]

Re: Outdrive quit while crusing

I was out on my boat and cruising at about 1/2 throttle when my out drive quit driving, it will not engage the prop in any gear. Does anyone have any ideas as to the possible causes? I'm hoping that it may be something simple. Its an Alpha One Mercruiser with a 350 engine. Thanks, Jim

Ayuh,.... What Vintage,..??

Pull the drive, 'n give it a good Inspection....
It Could be a blown prop hub, but usually the boat will still move, though Slowly...
It Could be a blown Coupler, which is mounted to the flywheel... You should be able to see it through the gimbel bearing after the drive is off...
It could be, depending on it's Vintage, the vertical shaft has broken at the o-ring groove,.. Pull the lower unit, off the upper, to see it...

 

[dubs283]

Re: Outdrive quit while crusing

list of possible causes:

spun prop hub - relatively cheap

spun enigine coupler - gotta pull the engine to replace, engine will overheat due to no power to waterpump

broken drive internals - rebuild or replace one or both drive halves

get the boat out of the water and pull the drive, check engine coupler splines and check drive operation

 

[jim9601]

Re: Outdrive quit while crusing

Thank you all for the advice, will let you know what the problem was. With luck it will just be the prop hub. I did get into some soft mud earlier, but just raised the out drive and eased out. Didn't seem to be any problems until I was planed off in deeper water. Thanks again

 

[jim9601]

Outdrive quit while crusing

Thank you all for the advice, will let you know what the problem was. With luck it will just be the prop hub. I did get into some soft mud earlier, but just raised the out drive and eased out. Didn't seem to be any problems until I was planed off in deeper water. Thanks again

Well I checked the prop hub, wasn't that. With the drive in forward I spun the prop by hand and I can hear and feel a clicking sound in the lower unit gear case, spinning the prop backwards, it turns hard. I'm guessing that it may be the shift isn't engaging the gear all the way? Looks like I'll be taking the out drive off and replacing anything that's wrong, and replacing anything that could go wrong down the road.

 

[stonyloam]

Re: Outdrive quit while crusing

. With the drive in forward I spun the prop by hand and I can hear and feel a clicking sound in the lower unit gear case, spinning the prop backwards, it turns hard. I'm guessing that it may be the shift isn't engaging the gear all the way? Looks like I'll be taking the out drive off and replacing anything that's wrong, and replacing anything that could go wrong down the road.

That is a clue. In forward you should be able to spin the prop freely (may click a little) it a clockwise direction. It should lock and NOT move ( it would have to turn the engine over to move) when you try to spin it counterclockwise. The shift is either in or out, no inbetween. If the prop turns with difficulty, but it turns in the CCW direction then something is broken. Could be prop hub, internal (outdrive) driveshaft, gears or coupler.

 

[Bondo]

Re: Outdrive quit while crusing

Well I checked the prop hub, wasn't that. With the drive in forward I spun the prop by hand and I can hear and feel a clicking sound in the lower unit gear case, spinning the prop backwards, it turns hard. I'm guessing that it may be the shift isn't engaging the gear all the way? Looks like I'll be taking the out drive off and replacing anything that's wrong, and replacing anything that could go wrong down the road.

Ayuh,.... Drop the lower unit, before ya pull the drive....
I'm guessin' the vertical shaft Broke, as I said above....
Yer turnin' the prop shaft, 'n the bottom of the vertical shaft,...
The resistance you feel is the impeller draggin'....
Yer Not turnin' the upper gears, nor the top input shaft into the motor...

The motor didn't turn, Right,..??

The clickin' is the opposite direction, 'n is the dog clutch rockin' over backwards...

 

[Don S]

Re: Outdrive quit while crusing

I would pull the drive and look at the splines in the coupler. If they are spun out, you won't turn the drive at all. After it quit working, did it overheat or did you run it enough to find out?

 

[pevaguy]

Re: Outdrive quit while crusing

No body has mentioned it, but how about the shift cable going to the outdrive? Could it be broken?

 

[ktbarrentine]

Re: Outdrive quit while crusing

Hmmmm...it's been a couple weeks now... Wonder what Jim found??

 

[jim9601]

Re: Outdrive quit while crusing

Jim found an out drive for $250 and switched them, I put the water muffs on it to test it and the engine runs hotter than normal, and it seems to grind in between forward (neutral) reverse. I'm thinking that maybe the cutoff isn't working, and thought I'd put her back in the water to see if the engine runs cooler. Does anyone know how to tell the difference between gen 1 and 2 out drive units, and if the gears are interchangeable? The cavitation plates and lift ram connection rod are different on the out drive I found, though other than what I said above, seems to work fine. I'm thinking that if I have to change the impeller, I may as well switch all the guts to the original out drive, if they are interchangeable. Any advice would be much appreciated, and thank you all for the previous advice. Will let you know what the open water test results were soon.

 

[ziggy]

Re: Outdrive quit while crusing

I put the water muffs on it to test it and the engine runs hotter than normal,

impeller is always the first place to look for running hot. imho, specially when ya just R&R the drive with an unknown condition drive.

and it seems to grind in between forward (neutral) reverse.

yep, alpha1's do that. nature of the dog clutch i think. to get it to stop doing that, make a snappy shift from neutral to rev. or fwd.

I'm thinking that maybe the cutoff isn't working,

that only works when the prop is under load. ie. in the water pushing the boat. how the shift interrupt system works. from the adults only sticky thread at the top of the i/o forum.

Does anyone know how to tell the difference between gen 1 and 2 out drive units

from the same sticky thread, How to ID an Alpha Style Outdrive, and History.
http://www.4shared.com/file/21385430...nd_Histor.html

and if the gears are interchangeable?

my 'guess' would be no. internals between even mc-1 and apha1 may not be interchangeable . whole uppers and whole lowers, yes, but not internals. to confirm, go look at a mercruiser parts link and see if the part numbers are the same between this drive and that drive.

I'm thinking that if I have to change the impeller

good idea!

I may as well switch all the guts to the original out drive, if they are interchangeable.

easy to say, likely hard to do. even if the parts are proper. yer gonna need to shim everything. requires many mercruiser only specialty tools.

Any advice would be much appreciated,

maybe an sei drive or have ya looked at the coupler (as mentioned earlier in this thread) to see if it's got any splines left on it. if not. nothing but replacing the coupler will make ya happy.

Will let you know what the open water test results were soon.

from your description, i'm guessing overheat is what the result will be. if it's the coupler, overheat will be the result too. bad coupler and bad impeller would be no cooling water being introduced to the engine.
imho, i've not seen ya respond to looking at the coupler yet. what'd it look like. sounds like ya got the drive off...

as for proper response from the prop to shifting.
fwd. and prop locks ccw, will spin cw w/ ratcheting sound and feel
neu. and prop free wheels. no feel, no sound, spins ccw and cw freely
rev. and the prop locks cw, will spin ccw w/ ratcheting sound and feel.

 

[ktbarrentine]

Re: Outdrive quit while crusing

So Jim...did you do any forensics on the old drive? I'd still like to hear what happened / what broke, and maybe see some photos. Inquiring minds, ya know! Good luck on the new setup.