To Rebuild or Replace - Cobra/SX outdrive

[MassFourWinns94]

Hi
I have a 94 Four Winns Horizon 190 - 5.0L, with a Cobra/Volva SX drive - 3868076 - so I guess its a Volvo-Penta SX kind of drive with an OMC label. Well, the boat is new to me and I spent alot of time inspecting the engine (also a VP plate on an engine with an OMC sticker that my mechanic calls a "Ford"). Being new to boating, well, I don't know where the "Ford" bit came from.

I should have looked at the drive a bit more - but when I winterized it, the mechanic changed the gear oil and it was a milky-water mess. Mechanic suggested that I look for a used/rebuilt Volvo SX drive instead of him tearing it down and replacing the leaking gasket(s). He thought it would be about $1000 to do the teardown/fix of the existing drive. And he thought it would be about the same price for a used/remanufactured unit.

The boat's history is mixed salt and fresh water, most recently lakes. I took it out 3 times before season end and it seemed to run OK - reaches about 45 mph no problem. Only issue it would stall when cold and I put it into reverse. If I let the engine warm, then it wouldn't stall. We are replacing the bellows this winter since they had some cracks.

I see SX drives for sale (1994-through 1998) - rebuilt/remanufactured - they seem to run around $2000 (not $1000), then I tack on a few hundred more for installation.

Anyone have any experience with the rebuild/versus buy used/reman? Hindsight 20/20 moments? Given that $1000 is easier to swallow than $2000+ - I'm leaning on having him fix the existing unit.

 

[Don S]

Re: To Rebuild or Replace - Cobra/SX outdrive

spent alot of time inspecting the engine (also a VP plate on an engine with an OMC sticker that my mechanic calls a "Ford"). Being new to boating, well, I don't know where the "Ford" bit came from.

If he is any kind of mechanic at all, he can probably just look at it and tell it's a Ford and not a Chevy.

5.0L, with a Cobra/Volva SX drive - 3868076

That 3868076 number says it's an SX outdrive, with a 1.66 gear ratio and was used on the 5.0L Ford carbed and injected engines.

What you need to do first is pull the outdrive off the boat and check for water in the bellows. If there is water in the bellows, then that is how it got into the drive.
You then need to drain and flush the outdrive and do a pressure check to find if there are other leaks.

 

[Jeepster04]

Re: To Rebuild or Replace - Cobra/SX outdrive

Why would he just up and say to replace the whole O/D without knowing anything about it? Just because it has some water in it doesnt mean that it needs to be replaced.

Do what don said and go from there.

 

[MassFourWinns94]

Re: To Rebuild or Replace - Cobra/SX outdrive

Hi
Thanks for the quick responses!
Yes, the bellows have a crack and there was water there. He didn't mention the bit about water in the bellows = water in the drive. I came to the shop in the afternoon and he had the drive off and the milky oil in the pan below the drive and told me he felt that something on the top, probably a gasket, was leaking and that it would be a full day to tear down and repair and rebuild and that was about $1000 and it might be cheaper to find a used one.

I'll have it pressure tested. It would seem to me that since the engine seemed to be turning the prop at the right RPM and the boat reached the correct speed for the prop/engine/rpm combo and nothing sounded bad, one wouldn't need to scrap the whole thing and buy a used replacement with even more mysteries behind that one.

 

[Don S]

Re: To Rebuild or Replace - Cobra/SX outdrive

I think you better find a real Volvo dealer, the guy you have working on it doen't appear to know what he is doing.
The bellows on those drives (with the drive off) takes less than an hour to change. You are also going to need a new gimbal bearing.
To remove 4 bolts and pull the upper carrier out of the drive and replace the seal, crush sleeve, bolt, and probably the ujoint assembly (Very spendy) will take another hour or two at most and that includes dumping some diesel fuel in the drive to flush it out.
With Volvo drives, a cheap used one (IF YOU COULD FIND ONE) is probably going to need the same thing as yours.
I have a funny feeling your mechanic understands Mercruiser alpha drives, not Volvo.

Milky oil in the drive does not automatically mean all the gears and bearings are bad, just that you have a leak. You will still need to pressure check it to make sure there aren't any other leaks.