Water in gear oil

[miles917]

1988 OMC Cobra 4.3l.

Recently pulled the sterndrive to replace the mystery screw on the port side of the outdrive which was never there when I bought the boat. Previously had no water in the gear oil when running for extended periods.

Re-installed the sterndrive, started it up had water coming out of the sterndrive near where I removed it. (bottom side, near bellows and where sterndrive mates up) I know I forgot to torque the 6 bolts.......

Pulled dipstick and very milky gear oil.

My first thought was bellows, which I learned I probably should have replaced as I know its been atleast a couple of years.

I pulled the outdrive today, clear water was in the lower bellow which I assume is exhaust and I think that makes sense. ??? Bellows look ok to the eye and no water was in the bellow that the u-joints and drive go through.

My question is where is the water coming into the oil. Could it be from the new gasket, not torqing the 6 bolts on the outdrive, bellows, etc.

I appreciate the knowledge guys, thank you and let me know if I'm not explaining well enough.

 

[danond]

Re: Water in gear oil

I can't necessarily answer your other questions but I can say the lower bellow should have water in it. That's your exhaust.

 

[jerryjerry05]

Re: Water in gear oil

Those drive can leak in a LOT of places.You need to have it pressure tested.
Drain it and put a pressure tester on it.It should hold 10-12# A local dealer can do it for you.Jerry

 

[miles917]

Re: Water in gear oil

Can I pressure test it myself? How would I go about doing that?

And assuming it didn't hold 10-12#, that would indicate bad seals? What would be the next step if if did/didn't hold pressure?

Thanks

 

[kikroks]

Re: Water in gear oil

y a you can test it your self you use a low presure pump similar to a vacume pump in reverse put the fitting from yur gear oil filler on the pump then apply soapy water arounf all areas and seals ,prop shaft upper to lower drive shaft water pump housing mating gaskets main driveshaft bearing seal , ya i know its impossible to do all these areas with out spliting the unit , well bust out a 9/16 wrench .

 

[miles917]

Re: Water in gear oil

Follow up, I've pressure tested the drive via the middle gear-oil hole. (fill hole)

I am not losing any pressure.

Exhaust bellow is toast as my finger went right through it. And that would be where I had water shooting out.

Would a faulty bellow allow water into my gear oil? It seems that this would not have anything to do with it.

Any ideas guys? Thanks

 

[miles917]

Re: Water in gear oil

I think I figured it out.......everybody is already out at the lake on their boats that run.....

Looks as though I'm going to purchase a seal kit for both the upper and lower gear housings. Any thoughts on this as to how difficult it will be and is there anything I should check first that could be a simplier reason as to why I am getting water in my gear oil.

Enjoy the water guys, I will too.......on a buddy's boat!

 

[a70eliminator]

Re: Water in gear oil

Did you drain all the oil when you pressure tested it? If not then your leak may have shown as an oil drip. The easiest place to check would be the fill plug gaskets, fishing line wrapped up on the prop shaft can destroy that seal.

 

[sea wolf]

Re: Water in gear oil

The exhaust bellows is designed with vent holes to relieve pressure, so don't replace it. Pull the water pump cover on the lower unit. Then remove the impeller housing. Look to see if there is gear oil leaking around the water pump shaft. If there is, then the seal is shot. You don't have to pull the drive to replace that seal. The hardest part is removing the adaptor housing. But, I would also do as someone else said & make sure u have good seals on all the lower unit plugs.

 

[miles917]

Re: Water in gear oil

I did drain all of the oil prior to the pressure test and it held approx. 10 psi without losing any.

I do not have a vacuum pressure tester so I have not been able to check if it holding vacuum. A local repair guy told me that test will tell me more than the pressure test.

As far as drain plugs washers/o-rings.......the boat was not in the water so I wouldn't think that much water could have gotten via those areas.

I did pull off the impeller housing and a little residual water in it was as clean as could be and I did not see any oil in the area.

Someday I hope to put this money pit on the water

 

[sea wolf]

Re: Water in gear oil

Did u check the prop shaft seal? Any oil leaks around the seal?

 

[miles917]

Re: Water in gear oil

Just wanted to throw this out there: I replaced the two o-rings and water pump shaft seal. (easy stuff first) Hooked up to water and ran....no water in gear oil. So I'm thinking I made a good guess and got lucky.

Took the thing to the water, ran for a while, checked gear oil and had water again.

I curious why I did not get water in with the muffs attahced. I did replace all of the plug washers.

Any ideas before I slip the halves?? Thanks