1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sitting

[chris0061]

I been working on this motor and got it running fine thanks to this website but now I have lower unit problems. I thought it was the prop shaft seal so I just replaced that. Took it to the river and ran it in the water and you could tell exhaust was blowing out lower unit oil. I let it sit and there is definitely lower unit oil draining down from the exhaust and water in the oil. Would shift shaft seal cause that or drive shaft seals????? It's the inline 6 115 hp.

 

[aussieflash]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Sounds like seals in water pump base need replacing,that will take care of drive shaft.I would also replace shift seal while your at it.
When draining LU check fill cap magnet for metal shavings.You don't want to see anything too chunky(bigger problem).Small shavings are normal/fine.Also don't forget to replace vent and fill screw gaskets...good luck.

 

[chris0061]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Fill magnet had just a little shavings on it when first taken off. Nothing at all worth worrying about. I'll pull the unit tomorrow and change those seals except is the shift shaft seal have any tricks to do??? Never done one before.

 

[Mi duckdown]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Is your lower end lube milky? it maybe unburnt fuel. I would do a pressure and vacuum on the lower end.
The lower end is a sealed unit.

 

[chris0061]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

yes 5 minutes backed in the boat ramp and running it milked it up pretty bad. It is definitely lower end grease in the exhaust hub.

 

[chris0061]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

anybody know off hand if the lower unit needs to be shifted in forward before you take it off. Book says forward for one type and neutral for another type lower unit but how do you identify which type you have?

 

[aussieflash]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Mine said same thing.I just did it in Neutral and had no problems.

 

[chris0061]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Got it off. put air to it and leaking on shift shaft. I wonder if I should replace the drive shaft seals while I'm at it.

 

[Chris1956]

Re: 1985 Mercury Mariner water in lower oil and oil comming out exhaust tub after sit

Yes, replace driveshaft seals, while you are at it. Inspect the driveshaft for wear where the seal rides. Clean the driveshaft with sandpaper, and lube it up. Now install a new waterpump base and seal, with new gasket and oring.