leaking gear oil where lower unit and midsection meet

[85merc200]

is this posible, i can swear thats where the oil is comming from while the motor is tilted, i've already the lower unit of the milkshake it had in it. I filled it up with new gear oil and now i believe i see where its comming from....thanks<br /><br />90's 5hp motor

 

[OBJ]

Re: leaking gear oil where lower unit and midsection meet

85....yeah it's possible. What your seeing, if it's dark black and thick, is unburnt oil from the exhaust seeping out 'tween the crack.<br /><br />Check the oil mix next time you fuel up. Maybe a decarb and make sure ya' got a good burn on each cylinder. Check the sparks are all good and spark plugs are up ta' snuff.<br /><br />Keep us posted.

 

[85merc200]

Re: leaking gear oil where lower unit and midsection meet

its not dark its the same yellow colored fresh gear oil i put it...mabey it could be comming from the shift rod seals?

 

[OBJ]

Re: leaking gear oil where lower unit and midsection meet

Well 85, that is a different story.<br /><br />It could be coming from the shift rod O-ring or the seals around the drive shaft. These are under the water pump housing.<br /><br />What I would suggest is to drop the lower unit, drain it and put a pressure test on it to determine which seal(s) are bad. Better yet, get a seal kit and just redo the whole lower unit.<br /><br />I sure wouldn't go near the water with a leaky lower unit.<br /><br />Get the service manual.