Alpha One Upper gears stripped. Is Lower unit ok?

Lift12

Seaman Apprentice
Joined
Oct 30, 2018
Messages
37
Hello!

I have been studying many of the very helpful posts here since I bought a 1989 Sea Ray 270 in September. Twin 5.7 GM, Alpha One (0C733590), both standard rotation. Second thing I bought was a service manual.

Short version:port drive upper gears destroyed themselves, I suspect due to loss of gear oil. Is there automatically Lower unit damage too? I plan to buy a complete upper. Should I be buying both?

History: Previous owner limped in on one engine. The boat was hauled shortly after and winterized. Drive and boat went untouched for a year until I bought it.

Less than half a quart of thick milky gear oil came out of the lower drain screw. No evidence of filings, surprisingly. Found an oily and greasy but water free mess in the bellows. Pressure test reveals leaks at the u joint seal in the upper and prop shaft seals in the lower. I have opened the upper case and found stripped gears and some filings, but not a lot.

Long term I plan to do as much maintenance as possible myself, and invest in the tools, but I'm not ready to deal with pressing gears, backlash, pre load, etc. I can manage the prop shaft seals and will invest in those tools if that's all it takes. If it's likely that there's expensive damage to the lower gears or bearings then I'd rather spend that money on a new complete aftermarket drive right now.

Thoughts?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,719
The lube does move a bit thru the drive but only thru a small hole. If anything go below it probably wouldn't be much. You could just get the upper (SCI) and check lower for metal in the drain screw. If rotating the lower by it self feels/sounds good, use it. If you notice problems later, it can be changed then.
 

Lift12

Seaman Apprentice
Joined
Oct 30, 2018
Messages
37
Thanks AllDodge. That was certainly my hope. I will buy the tools and pull the bearing carrier. With any luck it's clean in there.
 

Walt T

Lieutenant
Joined
Mar 16, 2002
Messages
1,369
You said the oil was milky which means water was in it. Could be rust in there now. Since you'll want to reseal the lower you'll see how it looks in there. Probably fine.
 
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