Mariner 40 gear lube and water mixing

[kuks24]

I have a mariner 40 hp that I just replaced the impeller with the two gaskets. I put the motor back together and refilled the gear lube, I took it out for a spin and when I got out of the water I noticed cream looking sludge coming out of exhaust on prop, so I pulled lower unit back off and it looks like that sludge is everywhere in the lower unit, so there must be a leak somewhere, any suggestions.

 

[RadarRick]

Re: Mariner 40 gear lube and water mixing

Could the sludge be unburnt oil/fuel. Does it smell a bit like gas? Gear oil smell is quite distinctive. Has the gear oil level dropped and what is it's condition? With such short run, it should look like new.

If sludge is gear oil, I would do pressure test to see where the leak(s) is coming from. Do a search to find plenty of info on pressure testing lower units.

 

[Silvertip]

Re: Mariner 40 gear lube and water mixing

In the process you must have dislodged the drive shaft seal. Oil is going up the shaft, into the pump, through the engine cooling system and out the exhaust. Or water is going the other way, into the lower unit, mixing with the oil and beiing expelled through the prop shaft seal.