Presuming you do not have the remote resevoir the only way for drive lube to
get into the boat is through the seal where the drive shaft enters the upper
unit. I would concentrate on figuring out how you're getting water into the
unit first. It should not be getting into the unit from the upper drive
shaft seal. That part is inside the bellows and if there was a water leak
you would be getting a lot of water in your boat. The seals are designed to
deal with a slight pressure but not a lot. The additional water could be
forcing the lube out. Or the loss of lube could be encouraging the water to
come in. The upper and lower units both have seals on the shafts going in
and out. On the lower this includes the shift shaft. They share the lube
through a hole in the cases with a o-ring on it where they bolt together,
not through the shafts. A shop would probably replace all the seals on the
upper and lower. It takes a number of specialized tools and you also should
check the gear setup and play when you put it back together. Closest auto
thing that comes to mind is installing a set of rear differential gears, the
mesh is adjustable. You could check around, some dealers would probably
give you a break if you bring the lower and upper units in alone. And
replace the water pump yourself when they're done. That would knock and
hour or two off the labor and keep them from having to jocky the boat
around. You'll want to get a service manual as the procedures for doing
anything to the drive are specific and not always obvious when you're just
unbolting things. I suspect from your post that you've not ever taken the
drive off, how it works will be a lot more obvious when you've done that
once.

"D.B." wrote in message
...
I have a 1989 Stingray with a 3.0 liter Mercruiser engine with an
Alpha one outdrive. I have been getting about a half a cup of water
in the foot after about every 4 hours of operation. I have been
changing the foot oil after every use (4hours) so as to keep things
from going poop until I could put it in the shop. I recently changed
from the expensive Mercruiser outdrive lube (quicksilver) to a cheaper
80W90 gear oil (seeing as I was changing it after every 4 hours of
operation). I have been noticing what I thought was gear oil in the
bilge, but was not sure until I changed lubes. Now I am positive that
I have gear oil from the foot in the bilge. My question(s) are
these.... would it be that the upper water seals in the outdrive are
causing the water to get into the foot and the oil to leak into the
bilge? Question number two....I am a decent mechanic.....without
having specialized tools, is it practical for me to replace the seals
myself (I did rebuild a Porsche motor several years ago....to give
you a benchmark of my mechanical capabilities)

Any help would be appreciated.

Dave