1966 Mercury 500 50hp looks like gear oil from the lower unit vent hole.

[TGB]

Is this normal or a sign of a real problem? I had new impeller installed recently and the gear oil changed. I have not had the motor on the water yet but did run it for about 20 minutes with muffs. It sat for two weeks and now I have noticed a puddle.

 

[carholme]

Re: 1966 Mercury 500 50hp looks like gear oil from the lower unit vent hole.

That drain hole is there to allow water to drain so that it does not freeze and rupture the case. When you doo see oil there it is indicative of a blown shift shaft seal, allowing LU oil to escape and drain out the drain hole.

Here is the parts listing for that engine:

http://www.crowleymarine.com/mercury-outboard/395.cfm

Item 15 in this link is the shift shaft seal which is leaking:

http://www.crowleymarine.com/mercury-outboard/parts/395_16.cfm

Gerry

 

[TGB]

Re: 1966 Mercury 500 50hp looks like gear oil from the lower unit vent hole.

That drain hole is there to allow water to drain so that it does not freeze and rupture the case. When you doo see oil there it is indicative of a blown shift shaft seal, allowing LU oil to escape and drain out the drain hole.

Here is the parts listing for that engine:

http://www.crowleymarine.com/mercury-outboard/395.cfm

Item 15 in this link is the shift shaft seal which is leaking:

http://www.crowleymarine.com/mercury-outboard/parts/395_16.cfm

Gerry

Thanks, Gerry
I have ordered the part!
Do you offer any advice on the install?