Milky Gear Lube and loosing gear Oil

Erick

New Member
Sep 29, 2021
10
Boat Info
2003 Sundancer 240
Engines
5.0 Mercruiser
I just bought a 2003 Sundancer 240 (5.0 Merc) with very low hours. I took the boat out twice and noticed the Gear Lube reservoir was decreasing each time I went out (last time it was almost empty). I do not see any oil in the driveway (boat is on trailer) or the bilge. I drained the oil and it looked a little milky. I put 10 lbs of pressure in the system and it held for 20+ minutes. I opened the reservoir and heard a hiss as it releived the pressure. Not sure when the last time it was changed but I know it was professional maintained but was out of the water for over 1 year before I purchased. Any other things I can check?
Thanks in advance.
 

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I would drain/refill and run it again.

keep in mind that the level in the reservoir will need to be topped off after the first few runs.
 
I would be suspect of lower unit seals. I know you said it held pressure, but that oil is going somewhere. If not in bilge or driveway, must be while yo are up ad running on plane. If it were me, I would have the lower unit serviced by a Certified Merc Tech to include seals. That way you know exactly where that drive stands.
 
I would be suspect of lower unit seals. I know you said it held pressure, but that oil is going somewhere. If not in bilge or driveway, must be while yo are up ad running on plane. If it were me, I would have the lower unit serviced by a Certified Merc Tech to include seals. That way you know exactly where that drive stands.
Just winterized, I might take the drive off and then I can drop it off somewhere to have them take a look at it.
 
Good luck Erick, pray its not leaking into bilge. Mine did and 2 years later i am still trying to clean that goop off the bilge floor, pumps, under unreachable sections under engine, its a mess.
I would guess with a 5.0 in a 240, you may be able to clean it up. A 7.4 crammed into a 250 not so much.
 
Last edited:
I'm told Simple Green is good to clean up oil in the bilge. The leaking drive has to be both pressure tested and vacum tested since some seals are to keep water out but other seals are to keep oil in.
 

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