Gear oil leaking merc 15 hp 2 STROKE

[maineiac5586]

I bought a 1991 mercury 15 2 STROKE LONGSHAFT. It was laying on its starboard side in my truck for 1 day. I took it out of the truck and saw a puddle of gear oil lying on the bed of truck. There is a decent size leak coming from a drain hole near the top of the lower unit next to the gear oil vent screw (tiny screw you take out to set the level) the screw is dry it is coming from a drain hole next to the screw. It is definitely gear oil and not residual 2 stroke oil as you may see sometimes. For reference this lower unit is the style with the water intake under the cavitation plate. Anybody care to guess what is going on? Thanks

 

[flyingscott]

Seal under the water pump is leaking. That lower unit is pretty crappy so you want to address any water leaks now. A pressure test is in order than probably a re-seal. Water destroys those pretty quickly.

 

[maineiac5586]

Ok. My guess was those SEALS as well. Can I pull the seal housing after removing the water pump? I would be leaving the DRIVESHAFT in place in the lower unit and removing the plastic base that holds the back to back SEALS to be replaced on work bench. Does that seem doable?

 

[flyingscott]

I believe it is but do all the seals. that lower unit is hard to find used and last time I looked was $1000 new. Then when the seal is out look to see if you have a bushing or bearing for the driveshaft. If you have a bushing make sure it is in good condition and there is minimal play in the driveshaft. If the bushing is bad replace it because the driveshaft will flop around and snap the pinion end off of it. If it is a bearing check to make sure it is good.

 

[maineiac5586]

Ok thanks