coolmedown

I have a Speedmaster 3 sterndrive that is requiring me to add oil to the stern mounted reservoir, about 1/4 - 1/2 qt., each time I go out on the water. It is not leaking the oil while sitting there on the trailer as there is no oil on the ground after sitting for a week. But it does appear that the oil is leaking in the bilge. I have searched on here but no one has discussed SSM III oil leaks. Here is the link that has the parts..

http://www.mercruiserparts.com/Show_...Y%28III+SSM%29

Im hoping someone can tell me which part # it is that is causing the leak. I just ordered a service manual. Thanks in advance for any replies that can aid me in servicing this drive.

tcelano

Well, here are the ways I see it could be leaking to the bilge:

1) if you have a cracked transom plate
2) the hose/fitting coming from the bottom of the transom plate oil tank has gone bad. Once the oil line connects to the gimbal housing, I'd expect any leak to be going to the ground, because that's outside the bellows.
3) The front seal at the input shaft leaking into the bellows


#1 could be fixed by just hooking up a new remote reservoir or replacing the transom plate (Let me know, I have two kicking around my shed).

#2 Replace the hose or fittings.

#3 Requires you to pull the drive (not hard at all with a III), and send the upper out to get rebuilt. You may be able to just change the seal yourself, but if you've got it off, it might be a good time to spend a couple hundred bucks and have someone like MRD go through it.

waybomb

When you get that manual, read about that "reservoir" bottle.

edit - now that I am home, in Service Manual HP-2, which covers III, II SSM, III SSM, IV SSM, V SSM, Under general information, page 1B-2, stated "Checking and Adding Stern Drive Oil", for units with standoffs or not, in big bold letters "Expansion Bottle, IMPORTANT: Oil reservoir is only used for drive unit oil expansion. Disregard "Oil Level Line" on reservoir sight window."

To check oil in a II through IV SMM:
1) Position stern drive unit so that anti ventilation plate is level
WARNING DO NOT remove oil vent plug when drive unit is hot from operation as hot, expanded oil may discharge if plug is removed.
2) Remove oil vent plug from drive shaft housing
3) Check oil level - oil should be even with bottom edge of oil vent hole. If oil is at proper level, reinstall vent plug and sealing washer. If oil is low, proceed to STEP 4
4) If oil level is low, plug oil vent hole (to create an air lock in drive unit), then, remove oil fill/drain plug, and insert Lubricant Pump into oil fill/drain hole.
and so on.

After I filled my bottles to the fill line, puking out a bunch of expensive oil into the bilge a couple of times, I read the book. That's how I found out about this. And this was after many here said I needed new reservoirs, which are actually used as expansion tanks.