Oil Leak from lower unit

mbacajun

Cadet
Joined
Mar 5, 2021
Messages
6
So I have an oil leak coming from the holes on the top front section of the lower gear casing. Does anyone know what these holes are for? How does oil get to these holes?
I would appreciate any help. I just bought this boat and it wasn't leaking when I looked at it. Sitting for about a couple of weeks and noticed oil on the concrete. Note: the pic is not the actual lower unit, however its shows the holes real good where the leak is coming from.
InkedMerCruiser -Alpha-Gen-2-Counter-Rotation-Lower-Unit_LI.jpg
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,986
Ayuh,..... Welcome Aboard,...... Those are weep holes to let any water outa the casting, so it won't freeze, 'n bust,.....

Leakin' oil from there, it could be comin' from the upper unit, or under the water pump, or from the shift spool,....
 

mbacajun

Cadet
Joined
Mar 5, 2021
Messages
6
Ayuh,..... Welcome Aboard,...... Those are weep holes to let any water outa the casting, so it won't freeze, 'n bust,.....

Leakin' oil from there, it could be comin' from the upper unit, or under the water pump, or from the shift spool,....
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
If you really want to know where the leak is, then you need to pressure test your drive. No one can tell you where it is other than that it is above the place where you see oil coming out. Can be in the lower or the upper gear case.

Building a pressure tester is easy.
 

mbacajun

Cadet
Joined
Mar 5, 2021
Messages
6
If you really want to know where the leak is, then you need to pressure test your drive. No one can tell you where it is other than that it is above the place where you see oil coming out. Can be in the lower or the upper gear case.

Building a pressure tester is easy.
So thanks for the reply. I've decided to take it to the shop to change all the upper and lower seals. I want to zero everything out and start fresh.
 
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