Water and Oil in outdrive, bellows, and bilge.

[jdeeewp]

Hello!

I have done some searching and can't really find what I am looking for.

I have a 1986 Mercruiser 4.3L 205hp Alpha 1 that has developed a leak in the outdrive.

2 weeks ago I changed the oil and impeller in the outdrive for the first time in over 3 years and found that half of what drained out was water.

I optimistically filled with fresh oil after a good drain and blow down using compressed air.

That weekend I dropped the boat off at the lake for the first time this year and noticed that the outdrive was VERY noisy. I am now thinking the drive is shot as it was stored outside all winter in New England and therefore most likely cracked and/or full of rusted gears.

I left the boat on the slip at the lake for 2 days and when I return, the bilge is full of water and gear oil. I bring it back home, consider some options and decide to swap the outdrive with a 'spare' from a 1972 merc 4 cyl 140 (IRON DUKE!). (I do realize the difference in gearing will likely mean re-prop)

When I pull my drive the bellows are full of water/oil.
I have finished swapping the yoke (V6 vs I4) and I am about to bolt it up but need to double check that I am not missing anything.

Please help!

Thanks!

Some other things to mention:
1. All bellows (gimbal/exahust/shift) and shift pin seal /bushing (transom side) were replaced by a professional just before last season and the boat spent all summer on the slip.
2. 3 years ago I lost a freeze/core/casting plug and burnt out/replaced all rubber on the exhaust path.

 

[alldodge]

I'm going to assume the oil you put in the drive was gear lube. With that, you have a leak in the drive and with that much water it should be easy to find. Without looking I will bet it is the input drive shaft seal, but you also would have a leak in the drive. When the drive is split, and then put back together you need to do a pressure test. How to do the test is in the top of this section in the DonS adults only area.

Check your gimbal bearing for wear and I'm sure it needs to be re-greased

 

[Bt Doctur]

So last season everything was normal? You never changed the impeller or oil in 3 years either?
~~That weekend I dropped the boat off at the lake for the first time this year and noticed that the outdrive was VERY noisy.
Did you replace the gimbal bearing?

 

[jdeeewp]

Yes, sorry, I guess I call gear lube oil sometimes.
I will be Greasing quite a bit as i reassemble.

BT Doctur, Yes i know 3 years is along time to go without outdrive servicing. I understand it is neglect that has gotten me in this situation.

Last year i noticed a whirring gear noise from the outdrive even when in neutral at idle, I knew I needed to get in there, but ran out of time last fall. I had assumed it was the water pump at the time. this year its the same until i get on the throttle in gear.

I am going to check the gimbal bearing when i put the new drive in and I will also be listening for noises. I haven't replaced it in the 4 years I have had the boat and don't plan on it unless its needed (probably before next year at this rate).

Thanks for your responses.

Anything else I may be missing? I was wondering if I would get the same symptoms from a bad bellows installation.

 

[Bt Doctur]

If you had water in the bellows the gimbal bearing needs to be replaced. If you install the drive correctly, glueing in the rubber ring in the housing you should not be getting water in the boat or the bellows. If you do have water entering ,there is a hole or an improper installation of the bellows.

 

[jdeeewp]

Alright, so I was betting on it being an upper half upper drive seal because of the gear oil in the bilge. If it was the bellows I wouldn’t find gear oil in the bilge, right?
I guess I will know if it continues with the different drive.

I have the spare drive bolted up. My plan is to drop the boat in run it for a bit and then pull the drive and check for water in the bellows.
Does that make sense?

The Gimbal bearing has been fully greased, water squirted water out. It moves freely but you can hear it a bit.
Can it wait for about an hour of runtime? I was really hoping to have a chance to confirm the spare drive is fully functional before spending more time/ money on this avenue.

Thanks again!

 

[Bt Doctur]

It is a upper seal from a rusted/grooved input yoke or a worn seal. it gets into the bellows, then into the bilge thru a vent hole in the housing.
you don't have to even run it, just let it sit and listen for some gurgling or bilge pump operation.
Yes, if the bearing dosent grenade itself first.

 

[jdeeewp]

alright, Drive two is functional! YAY enjoyed an afternoon on the boat the other day. Taking it easy of course, trying to get a feel of confidence in the new setup and all.

And then today I go to cover it up for the week and notice yet more oil in the bilge. boo! so now I am thinking it may be the bellows.
Does that make sense assuming there are no seal issues in the replacement outdrive? I feel like there would be more water in the boat if it were the bellows.

I guess I am looking for other ideas at this point. I am 85% sure its not engine oil but either way i will have to pull the drive to check for water in the bellows soon.