48 Special Lower Unit Weep hole leaking gear lube

69starcraft

Petty Officer 2nd Class
Joined
Jul 11, 2007
Messages
169
Noticed yesterday after running the motor in a barrel for a bit that I had a thick looking oil coming from a small weep hole on my lower unit. It is on the starboard side right below the water inlet holes.

Since I haven't done anything but idle her once or twice in the barrel so far decided was a good idea to get around to checking the Lower unit oil.

Pulled the plugs, came out pretty Grey. :(

So I let her drain, and then refilled the L/U with fresh oil.

I was going to run again in a bucket later and see what happens when I check it again.

However, I STILL have a small amount of gear oil coming from this weep hole. I drew a crude circle around the weep hole, and a crude arrow pointing to a Phillips screw of which the function I am unsure since there is also a top and bottom Flathead drain screw??

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From what I read by searching the forums this hole is supposed to be for draining unburned exhaust oil/gas but mine is definitly leaking gear lube.

I'm a mechanic by trade, I know the difference and it's hard not to notice that rotten smell.


So my question is what seal is bad or what could be wrong that would cause the fresh gear oil to weep from this hole? :confused:

An overnight sit had produced enough leak that there was a "drop" of lower unit lube hanging from the skeg, but none had actually dripped to the ground. So it's not leaking very fast at all. But oil out can mean water in.

Since I have fresh oil in it now would it be all right to take to the lake and at least run it for a sea trail (then come home and check oil again) I've never used it yet, but verified Fwd and reverse and no scary noises while running in the barrel. I would like to at LEAST try it once, and then maybe rebuild the L/U or sell the boat


BTW I saw no Nylon washers on the Drain Screws....the screws have rubber washers look like they are built onto the screw. I will be replacing them

I have a Seloc manual but as I found out (and you already know) they are not so good...
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
Re: 48 Special Lower Unit Weep hole leaking gear lube

You did not tell us the year so have not been able to look at any diagrams.

However I think that weep hole is the drain for the water intake cavity.(there'll be a strainer in there I expect) If LU oil is getting into the water intake area then it is almost certainly the seals on the vertical drive shaft that are leaking.
A pressure test is of course what the pros would do to confirm.

Oil wont actually leak from the seals while it is standing upright, I think they are above the oil level, but they will leak when it runs.

DONT UNDO THE PHILIPS SCREW it holds internal parts in place (Pinion bearing I think in that position)

Some have O rings on the level and drain plugs I believe. Renew them.

By all means give it a short run on the lake. I would not panic over a little fresh water getting in. Sea water would be more serious

If you do have to replace the driveshaft seals overhaul the water pump at the same time, maybe also the seals on the shift rod. You dont want to have to go in there again for a few years. But the work necessary stops well short of rebuilding the whole LU.
 

69starcraft

Petty Officer 2nd Class
Joined
Jul 11, 2007
Messages
169
Re: 1987 48 Special Lower Unit Weep hole leaking gear lube

Re: 1987 48 Special Lower Unit Weep hole leaking gear lube

Sorry the year is 1987

oops! I have already removed the phillips screw....a little gear lube came out but nothing else, and screw went right back in where it came from

Think I am ok there?

#$$%^#@ I hate when that happens!
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
Re: 48 Special Lower Unit Weep hole leaking gear lube

Looked at the diagram of the gearcase. Nothing different to say, pretty much as i expected.

Nylon washers and O rings are both listed as seals for the plugs. Pays your money and takes your pick I suppose ?

Trouble with the Philips screws is that on some models there is one lower down that carries part of the gear shift mecahnism. If you take that out and the bits inside move you have problems!

BTW there is a seal on that Philips screw
 
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