Logo
FULL SITE MENU

Oil Drip. Serious?

P

pugetsounder

Advanced Contributor
OK here's the scoop:

1982 pre-alpha. I took the drive off last fall, replaced water pump, base, all gaskets, etc, etc. Pressurized the unit back then, checked out OK. Fast forward to this past Sunday. I thought the weather was getting nice enough to start putting the boat back together and get it ready for summer. As I was hauling the drive out to the boat I noticed an oil drip of a couple of drops coming from a weep hole just above the prop bulb on the forward/starboard side of the unit. Pissed, I drug the unit back to the basement and did another pressure test. It held 30 psi for 20 minutes and no drip out of the weep hole! I'm pretty confident the unit is sealed but what the heck is with this drip of oil. And what does the weep hole connect to? I figure it was a water drain of some sort. Any thoughts before I bolt the drive back on the boat?
 
Could have been the normal 'drip' when you separate the upper and the lower....just took a while to drain out.

If its the hole I think it is, it lets the water out of the front 'pocket' in the lower.

30 PSI is a bit high to test those drives; that said, make sure you filled it with oil and go try it out. check it after the run and a couple runs after that. If good then, you should be good for the rest of the season. Could always spend a few bucks on a drive oil reservoir kit.
 
First drain the oil and recheck.

PSI for pressure chscking is not specified by merc that I am aware of.

OMC specified ~18 psi to pressure check there outdrives.

I use and have used for years 15-18 psi.

There is no need for any more as the outdrive may produce only ~7 psi when running.

Leaks may not show up with oil in the drive.......it should be empty.
 
OK Thanks guys. I figured @ 30PSI if there was a weak spot anywhere it would've showed up, but it held fine. If 30 PSI can't get out I don't think water can get in. I checked it dry last fall and full of oil a couple days ago and it's all good. I think I'll go ahead and bolt it up and check it after my first launch and periodically through the season.
 
pugetsounder said:
If 30 PSI can't get out I don't think water can get in.
Click to expand...

it can

the pressure behind the lip of the seal helps it seal. At 30 psi you were really pushing the lips tight onto the shaft

When a drive cools down after a run, a vacuum is formed inside the drive which can pull a weak lip seal off the shaft and draw water in.
 
Agree with hystat.

If there is a leak and a pressure ckeck does not show it, I also pull a vaccum on it. I have both tools.............

Typically a leak will show with a pressure check, If water is in the oil and a pressure check does not show a leak then you must pull a vaccum to find it. As said when it colls or a lack of pressue a vaccum situation can occur and pull the water in.
 
Thanks for the headsup. Like I said I'll check after the first run of the season. I'll run it long and hard and let it sit for a few. Bring it back to my driveway and then check it for any water intrusion. Like was said before it could've been run off from seperating the halves as well but better to check it regularly just in case. If it leaks water then I pull it a part again.

Just curious what could be leaking oil into that particular gallery? If it's just a water pump base gasket no problem. The water pump base has a brand new seal as well. If it's something else I can't figure out what.
 
Last edited:
This oil drip is out to get me. I pressure tested the drive, no drip. It sat in my basement in the upright position for two weeks, no drip. I install the drive on my boat and a few days later I have a constant drip coming out of the same weep hole! It's been in the completely lowered position so the drive is upright. I don't get it :confused: It's peculiar that pressure won't force oil out of it but gravity will.

Anybody have a guess on what seal would be leaking out of that hole? I'm trying to think if it could be the work I did like replacing the waterpump base and gaskets but I can't figure out how oil would get to the drain area of the drive. I assume the the drain hole is not connected to the exhaust chamber? I'm hoping it's not a shaft or bearing seal but if it is I have my old lower that I know is in good shape.
 
No matter what, a drip is a leak and a leak leads to a failure in the upper from being low on oil. You have a choice to make"Pay Me Now Or You will Be Paying Me Later."
Only you can decide on where your going to be buying a new drive not counting the towing bill back to your port.Last check it was like $125.00/Hr port to port.
 
Chief, good guess but I don't think so. I thought of that too. If that o-ring was ripped I don't think it would hold pressure and oil would drip either outside where the drive halves meet or into the exhaust chamber. The exhaust chamber is clean and dry of oil.

Bt Doctor, I get it that's why I'm asking for advice before I put it in the water.

Does anybody have a cut away pic of the Alpha drive? I might be able to figure out what is leaking if I can get a look at the insides of the drive. It's got to be some shaft seal some where.

The bright side is other than this drip my boat is ready to hit the water. Getting excited for boating season.
 
Last edited:
HAHA I know my eyes are going bad but you should check you glasses. The link says #50 - oil seal. #49 is the bushing. But I get what you're saying. Yes that chamber is a water drain but how oil is getting in there is the 100,000 question. But now I'm not sure it's that oil seal. Hoping it's not a cracked casing.

But if it is, like I said earlier I have a good lower I can just swap over with the drive connected to the boat. I may just do that anyway to get on the water and fix this one later.
 
Back
Top