Mercruiser inboard/outboard lower unit question

[addict2fishing]

I have a 86 17ft Glastron with a 140 hp inboard/outboard I have noticed there is gear oil coming out of a little hole on the front of bottom of the outboard in the up position in my garage, is this a problem or normal?

 

[Gary H NC]

Re: Mercruiser inboard/outboard lower unit question

No gear oil leak is normal.It is a sealed unit so it sounds like time to have it pressure tested.
Also a good time to drain the gear lube and see if it has water intrusion.

 

[ziggy]

Re: Mercruiser inboard/outboard lower unit question

^
agreed.
the drive is a sealed unit. there should be no leaks.

go up to the adults only sticky and read up on the pressure testing thread. pressure/vac testing can help you locate the leak.
my speculation would be a shift shaft seal. but the test will tell for sure where it's at.

 

[MRS]

Re: Mercruiser inboard/outboard lower unit question

You should never leak oil at all if you do you need to figure out where and why. Like ziggy said it is probably the shift shaft seal so get your manual out and start checking. I did have a merc 120 and it leaked like you said in the same area it was the shift shaft seal.

 

[havasuboatman]

Re: Mercruiser inboard/outboard lower unit question

That little hole is for draining water from the casting pocket where the shift shaft goes into the lower unit. Seperate the upper from the lower and you will most likely find that is where you are leaking.
No point in pressure testing the drive. It leaks. Oil coming out that little hole means its leaking between the upper and lower so a bubble (soapy water) test wont work.
Time to reseal. If your drive is more than a few years old, I reccomend resealing the whole drive.
You also need to make sure your drive doesn't have water in it. If gravity will force oil out, water is probably going to be an issue.

 

[addict2fishing]

Re: Mercruiser inboard/outboard lower unit question

Thanks for all of the responses I guess I will Boat =Break Out Another Thousand!!
Does anyone have an idea of the cost to repair?

 

[Don S]

Re: Mercruiser inboard/outboard lower unit question

Thanks for all of the responses I guess I will Boat =Break Out Another Thousand!!
Does anyone have an idea of the cost to repair?

You can't estimate the cost to repair, if you don't know what's wrong.
You can expect it to take up to an hour to pull the drive, drain the gear lube, do a pressure and vacuum check just to find out what is leaking.

 

[jtybt]

Re: Mercruiser inboard/outboard lower unit question

See if it's co ming from the fill/drain screw and drain a little oil to see if there's water contamination. If it's not coming from the drain plug and it IS coming from the 'pee' hole, most likely the shift bushing is leaking. It is often overlooked or ignored and can be a PITA to remove the top 'nut' but it's simple to fix.