omc cobra leaking oil into bilge

[tonyjklh]

hello everyone im new to the forum, couldn't seem to find what I need so I'll see if someone knows.
I recently purchased a 1988 bayliner 1950 open bow. the boat sat unused for 3 years. its now running great other than the esa switches sticking. the problem is I've noticed oil inside the bilge after every trip. engine is always full. but the outdrive is not. so im assuming its got a bad seal and leaking into the boat. there is never any water in the drive so none of the seals in contact with the water is bad.
am I assuming all this correctly?
so the question would be how hard is it to pull the drive and change the seal?
or is the engine required to be pulled to change it?
and what is the procedure for pulling the drive?
I am very skilled with mechanical work so the job wont be a problem once I have a general idea of the procedure.
thanks for any advice

 

[Reinell-BRXL-191]

Re: omc cobra leaking oil into bilge

Don't know the exact specs for your engine or drive, but here is some food for thought... besides for hydro lines to the trim cylinders, there is no oil exchanged from the outdrive to the engine compartment.. if the engine is not losing oil, it could be the trim pump or the power steering leaking in to the bilge..

I currently have a bad actuator leaking fluid in to my bilge, only after it is shut off and sitting... The previous owner used to turn the drive from side to side with the trim rams, This is a NO NO... matter of fact, I just saw a video on here, where someone was turning the pivot housing with the trim rams.. the actuator is not designed to work in reverse, and it causes a lot of pressure on the ram seal in the unit... and a good amount of time, will rupture that seal and cause a leak, run your hand under the power steering actuator.. I will bet you pull back a oily paw... but don't worry about oil coming in from the drive to the engine compartment.. the OMC drives are sealed units ( if we are talking about a cobra)

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

Don't know the exact specs for your engine or drive, but here is some food for thought... besides for hydro lines to the trim cylinders, there is no oil exchanged from the outdrive to the engine compartment.. if the engine is not losing oil, it could be the trim pump or the power steering leaking in to the bilge..

I currently have a bad actuator leaking fluid in to my bilge, only after it is shut off and sitting... The previous owner used to turn the drive from side to side with the trim rams, This is a NO NO... matter of fact, I just saw a video on here, where someone was turning the pivot housing with the trim rams.. the actuator is not designed to work in reverse, and it causes a lot of pressure on the ram seal in the unit... and a good amount of time, will rupture that seal and cause a leak, run your hand under the power steering actuator.. I will bet you pull back a oily paw... but don't worry about oil coming in from the drive to the engine compartment.. the OMC drives are sealed units ( if we are talking about a cobra)

well my boat does not have power steering so that's not it. I know the drive is sealed and isn't supposed to have oil going towards the engine. but seals can go bad. the drive is loosing oil and needs to be toped off every trip. there is no oil leaking on the outside of the drive so this is why im thinking the oil in the bilge is from bad seals on the drive going through the bellow into the boat. definitely not hydraulic fluid that's leaking so not the trim pump.

 

[Reinell-BRXL-191]

Re: omc cobra leaking oil into bilge

well, the only other thing that it could be is a seal behind the drive shaft on the upper unit... if that is leaking, the oil will travel thru the bellows and drip in to engine compartment... you have to pull the outdrive to check... if that's what it is, it will be a mess in there

Just take the 6 - 7/16th nuts off that hold the drive and yank... it comes right off, make sure the shifter is in neutral and the drive is trimmed down

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

well, the only other thing that it could be is a seal behind the drive shaft on the upper unit... if that is leaking, the oil will travel thru the bellows and drip in to engine compartment... you have to pull the outdrive to check... if that's what it is, it will be a mess in there

Just take the 6 - 7/16th nuts off that hold the drive and yank... it comes right off, make sure the shifter is in neutral and the drive is trimmed down

ok sounds simple enough. will I need the alignment tool to just check(and possible change) the seal?

 

[Levinz11]

Re: omc cobra leaking oil into bilge

ok sounds simple enough. will I need the alignment tool to just check(and possible change) the seal?

Yep. Anytime the drive comes off it will need to be re-aligned. Should be done annually anyway.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

Yep. Anytime the drive comes off it will need to be re-aligned. Should be done annually anyway.

ok thanks. I will order the tool as well as a manual after I pull the drive and see if anything else needs replaced while its off.

 

[HCMQA]

Re: omc cobra leaking oil into bilge

How are you checking to see if water is in the drive? You cannot check for water with the dip stick at the top.

If you are getting that much oil in the engine bay it is getting past the gimble bearing and two very tight o rings. Plus the drive shaft would fling it all over the place in back of the engine. Are you just getting a tiny amount?

What engine do you have? I am surprised that an 88 would not have power steering.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

How are you checking to see if water is in the drive? You cannot check for water with the dip stick at the top.

If you are getting that much oil in the engine bay it is getting past the gimble bearing and two very tight o rings. Plus the drive shaft would fling it all over the place in back of the engine. Are you just getting a tiny amount?

What engine do you have? I am surprised that an 88 would not have power steering.

ive got a 3.0L engine. I've been checking for water by draining all the oil from the drive. there is a fair amount of oil getting in. when I get back from a day on the lake there is always a good film of oil over the water in the bilge(I know shouldn't be water in there either but haven't yet found where that leak is). before I spend a lot of time degreasing and cleaning all the oil in there I want to fix the leak.
so now im assuming there are two more seals/O-rings that are also going to be bad? to me it seems strange that 3 seals could be bad to let the oil leak in. but the drive is the only thing I have to keep filling up so I its gotta be it. would the upper seal kit I purchased have those two O-rings in it(bought the whole seal kit because it wasn't much more than the shaft seal alone)

 

[Levinz11]

Re: omc cobra leaking oil into bilge

HCMQA is right... I think. Your boat should have power steering. Take a pic of the engine compartment.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

HCMQA is right... I think. Your boat should have power steering. Take a pic of the engine compartment.

nope no power steering, unfortunately

 

[Levinz11]

Re: omc cobra leaking oil into bilge

Hmpf. Clean everything really well with Simple Green...run her...find your source of oil.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

Hmpf. Clean everything really well with Simple Green...run her...find your source of oil.

the oil is running in from behind the engine through the cover plate on the bottom. I originally thought it was the rear main seal because of the location the oil is from, but being the oil level in the engine has not gone down at all after many days on the lake that's definitely not it. that's where I stated getting the idea that it might be coming from the drive.

 

[Reinell-BRXL-191]

Re: omc cobra leaking oil into bilge

Well, just know that 1 oz of oil can make a mess when mixed with water, and look like a lot more than it is.. my actuator leaks maybe one oz after it sits, and that makes a trail 2 inches wide all the way to the front of the motor.. and an oz of oil won't show missing on the dipstick... but it's easy to pull the sterndrive... and you will know by what it looks like in the bellows as to whats going on... if you have the means, I would go ahead and replace the bellows and shift cable if you have any doubts as to how old they are... kill as many birds as you can...

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

Well, just know that 1 oz of oil can make a mess when mixed with water, and look like a lot more than it is.. my actuator leaks maybe one oz after it sits, and that makes a trail 2 inches wide all the way to the front of the motor.. and an oz of oil won't show missing on the dipstick... but it's easy to pull the sterndrive... and you will know by what it looks like in the bellows as to whats going on... if you have the means, I would go ahead and replace the bellows and shift cable if you have any doubts as to how old they are... kill as many birds as you can...

i am replacing the u-joint bellow since its starting to crack. the exhaust bellow has a lot of cracks in it but i don't see a big problem with that one leaking since its full of water anyways. i think for now i'll hold off on changing the shift cable since it shifts real nice right now and the cable is nice and smooth even when moving it by hand.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

am I correct to assume that the exhaust bellow is ok to be leaking a little through some cracks?

 

[Don S]

Re: omc cobra leaking oil into bilge

Yep. Anytime the drive comes off it will need to be re-aligned. Should be done annually anyway.

Just a note on this. Anytime the drive comes off the alignment needs to be checked. It should NOT need to be re-aligned. If it does need to be realigned, then you really need to find out why. The alignment should not change from year to year unless something has gone wrong. And yes, I should be checked at least annually, and grease the coupler splines at the same time.

If you are getting water in the drive, remove the drive, check the bellows for water, drain the drive and pressure check it. 15 PSI and spray some soapy water everywhere to find the leak.
When you get water in the bellows, it gets into the drive, then the drive pushes oil into the bellows which can and does get into the bilge.

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

Just a note on this. Anytime the drive comes off the alignment needs to be checked. It should NOT need to be re-aligned. If it does need to be realigned, then you really need to find out why. The alignment should not change from year to year unless something has gone wrong. And yes, I should be checked at least annually, and grease the coupler splines at the same time.

If you are getting water in the drive, remove the drive, check the bellows for water, drain the drive and pressure check it. 15 PSI and spray some soapy water everywhere to find the leak.
When you get water in the bellows, it gets into the drive, then the drive pushes oil into the bellows which can and does get into the bilge.

good info about the alignment. I've drained the oil every couple trips to the lake to make sure there was no water getting in, and hasn't had any yet, not even in the old oil I replaced when I got the boat, but I'll definitely test it with air pressure. I understand what you are saying if water is getting into the upper(u-joint) bellow. but what about the bottom? isn't that one open to the water all the time anyways for the exhaust and cooling water to go out through?

 

[Reinell-BRXL-191]

Re: omc cobra leaking oil into bilge

The exhaust bellows is allowed to have water in it... matter of fact, the engine pumps water in to it and out in to the lake... so, there is no sweating any water leaks there...

 

[tonyjklh]

Re: omc cobra leaking oil into bilge

i have the drive off and the bellows was full of oil and water. this is definitally where my problem is from. ive already removed the shaft/carrier assembly from the drive. spent about 2 hours making a tool to remove the spanner nut. got the new seal in so all that's left is to put it all back together.