OMC Cobra leaking milky gear oil from water inlets (new thread)

[HSBarker81]

I noticed today that my 1994 OMC Cobra outdrive is leaking milky gear oil from the water intlets. What would cause this and could it be related to my planing issues?

Thanks,
Harley

 

[marunr]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

Have you checked your gear oil? If it's coming out there, it must be leaking out of the main bearing carrier and running down in to the water inlet. That would mean the bellows and gasket are bad and you have water and oil mixing together.
Either that or you have a cracked housing somewhere.

I would drain the gear oil and pull the drive for inspection.

 

[bruceb58]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

There are a number of places that you can have a bad seal and you would see oil at the water intake one of which is the seal for the shaft of the water pump. Best bet is to drain the drive and do a pressure test.

Really not sure what marunr is talking about because if the seal he is talking about leaked, it would leak into the bellows and stay there.

This would not be related to you planing issue.

 

[marunr]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

I was thinking the oil must be leaking around the bellows lip and then, if the pivot housing gasket was bad, it would end up mixing with water running through the water intake chamber. Pretty unlikely, and I had not thought about the water pump shaft seal. Sorry!

Anyway, I think the drive needs to come off.

 

[Boatin Bob]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

Guys if this is truly a 94 then the raw water pump is belt driven off the engine. I think the best plan though is to check the lube and then remove the drive and do a pressure/vacumn test.

 

[bruceb58]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

Bob,

You are correct, water pump was no longer on the drive in 94. This was the drive that was like the Volvo by then.

Does your boat have the water pump on the back of the drive? Some 94 boats would still have the 93 drives.

 

[HSBarker81]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

A year ago, I had a local shop replace the bellows and do a pressure/vaccum check on the drive. I also has the manifolds and risers replaced at this time. I'm wondering if maybe this is something I can have them fix...I guess if the check was good at that time, none of the seals would have been replaced, therefore nothing would be covered by them.

As far as the water pump, i know it has a standard one on the front of the engine, where should I look for the one you're asking about?

Thanks,
Harley

 

[Don S]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

Pull the plastic cover off the back of the outdrive. Under it is either a raw water pump or shift linkage, which do you have?

 

[MJ76]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

I believe that the VP SX, which does have a belt-driven water pump, did not come out until 96. The 94 Cobra will have the raw water pump in the drive. If the milky oil is coming from the water inlets, the gear lube leak is almost certainly from the small seals at the water pump shaft, behind the impeller plate. A pressure test will confirm this.

 

[bruceb58]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

94 is when they moved the raw water pump off the drive. The big question is if your boat has a 93 or 94 drive.

 

[Don S]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

The MD models were 93-94 production year of the first Volvo/OMC joint venture. The year of the NEWEST version of the "King Cobra"
Have a look at this Volvo bulletin.

Volvo Engine ID

 

[Boatin Bob]

Re: OMC Cobra leaking milky gear oil from water inlets (new thread)

It should be very easy to tell if you have the belt driven water pump as it will have 2 fairly large black hoses attached to the rear of it, one hose comes from the transom, the other should feed the t-stat housing. If you know or can read the engine model number off the plate on the rocker cover or t-stat hosuing then we would know for sure but 99.9 % sure you have a belt driven raw water pump inside. (as long as it's a 1994!)