Sterndrive lub.

[Lucky Penny]

I have just finished doing my 50 hour check on my Alfa Drive (360 Mercruiser) and when I opened the vent screw it oil was under pretty good pressure the oil came blowing out. I would say 2-4 oz. What surprised me more than that was the color, it was slightly milky.

For the life of me I can not understand how water got in, especially with pressure in the chamber. being pressurized there would have to be a leak somewhere, but noting, she is tight.

any one have any idea's on how the water got there?

 

[HT32BSX115]

Re: Sterndrive lub.

You have a leak in a seal.

When you start up and run the drive it heats up. when it cools it causes air inside to contract and suck in water thru a leaky seal if it sits in the water during the cool down.

It doesn't take much to give it a milky color. You need to flush it out, get it resealed and pressure checked.

Once there's water in there heating and cooling will cause the water to produce vapor (steam) which will expand and contract with drive temp.


Cheers,


Rick

 

[Lucky Penny]

Re: Sterndrive lub.

I can understand a leaky seal, but a leak would work both ways. If water is getting in, then oil or air should be getting out, especially under as much pressure as I found. Also, the engine had not been run for about 10 days. I checked the drive and the ground under it, and there was not trace of oil. This is what is confusing me.

I know the only way for the system to pressurize is to add fluid. Also, the oil was not overly milkie, it was a tan color.

 

[Don S]

Re: Sterndrive lub.

If water is getting in, then oil or air should be getting out.

Not exactly, there are double lipped seals, and double seals. So it can and does leak one way and not the other.
What year is this Alpha? 50 hrs on it, is this a new Alpha I or an Alpha I Gen II?
The Gen II drives MAY have a reservoir and shouldn't hold pressure like that.

 

[Lucky Penny]

Re: Sterndrive lub.

The drive is one of the older R/MR/Alfa's about a year ago it was pulled off and all the seals replaced (preventively) up till today, I have not had a single drip of a problem with it. shifts smooth, runs quite, gets me from point 'a' to point 'b' and back.

Which seal would be suspect for a condition like this?

Like I said the volumn is correct, so nothing is being lost.

Jon f

 

[eddy pons]

Re: Sterndrive lub.

before you go crazy looking for a bad seal,first you must drain the whole i/o and inspect the oil, sometimes when you run the motor for a while the the oil will foam up giving it the appearance of water mixed in with the oil,,drain it and let it be for a while,,if confirmed that you are geting water,check your drain gaskets,remove the prop,check for fishing line behind the prop,unless you know how to do your own repair EXMpl,,water pump base, shift shaft bushing,lower gear seals in the upper half you should take it back to the repair shop,,,they might be able to put a vacum tester to find the problem,,hopes this helps,,,,

 

[Don S]

Re: Sterndrive lub.

Pull the drive and make sure there isn't any water in the bellows. If there is, that is how water got into the drive. The input shaft seal is not designed to keep water out, (that is the job of the bellows) only to keep oil in.
As water is sucked in from the bellows, as it cools after a run, there is not as much room for expansion and it will blow past the front seal into the bellows.
It's usually a milky brown, nasty mess.

 

[Lucky Penny]

Re: Sterndrive lub.

I think I may have been a bit remiss when I started. When I drained the oil it started to come out the normal old oil green, then started to show signs of milky 'stuff' when I transfered it to a clear container to allow it to settle it all mixed together and it is all an old looking oil right now. I should say that the milky oil shot out of the vent when I removed the screw, so it was on top of the oil.

Just to give you an idea of why I am so paranoid about the boat. For 6 months a year she is my home. I am retired Navy and work a few months at a time as a Paramedic/Scrub Nurse along the east coast to make ends meet. My little 24 foot Winner Express Cruiser has proven to be very comfortable for me and the dog (a Scotty.) Especially since I remodelled the interior, making it roomer.

With this being said, whenever anything starts to go the wrong way, it means I may not be able to take a job, or get stuck somewhere other than home.

I appreciate everyone help, and I hope this little glitch turns out to be nothing.

JON

 

[Don S]

Re: Sterndrive lub.

Since you say it's green, you are probably using the Merc Hi-Performance gear lube, and it will not seperate water from the oil no matter how long you let it set. It's designed and has additives to keep it mixed up so you don't have "Just water" in the bottom of your drive.
If it's just a few streaks, it's not a problem.
But your really do need to pull your drive and check the bellows at the end of the season. If you leave water in it all winter, you will have an expensive repair.

 

[Lucky Penny]

Re: Sterndrive lub.

Thanks for the info.

I use the boat all year round, and even sitting pierside I run the engine at least once ever two or three days, even for just a short period of time. I do try to set underway on my days off, sometimes to just do a bit of fishing, or just seeing the local sights.

One question about the Bellows. I have had a leaky drive shaft bellows before and almost alway get water in the bildge. Right now the bildge is dry and as best as I can see (Mercruiser does not get one a lot of room back there) there is not water coming through the drive shaft access.

 

[Don S]

Re: Sterndrive lub.

The fact remains, you need to pull the drive once a year or every 100 hours if for nothing more than to grease the splines in the coupler. Every 50 hours if you do a lot of idling or trolling.
You should still be checking the alignment, ujoints, gimbal bearing etc. It's just preventive maintenance.
Hopefully grease isn't plugging up the hole that lets the water into the boat.

 

[BAYLINER185]

Re: Sterndrive lub.

Hopefully grease isn't plugging up the hole that lets the water into the boat.
----------------------------------------QUOTE--------------------------


WHAT!

What hole Don? are you supposed to get a little water in the bildge area at the end of the day?

 

[eddy pons]

Re: Sterndrive lub.

the hole he is talking about is a vent hole in the area of the gimball bearing its design to releave presure inside theu-joint bellow area,,if you get a hole in your bellow the water will also enter the boat through this hole,,sometimes if the water is inthere for a long period of time your upper seal will leak oil out mix with the water and enter the boat smells like a sewer,,you might not have that problem but i,m with don about taking i/o off every year for inspection you will save a lot of money in the end run,,,

 

[BAYLINER185]

Re: Sterndrive lub.

OK cool I knew I was missunderstanding somethign.. I DONT have that peoblem !