How Much Mousse is Too Much?

[quinnf]

I just changed the gear lube in the lower unit of my 1989 Evin. 120. Boat and engine were new to me last August, so I don't know when lube was last changed. A small quantity of light brown mousse was discharged along with the black gear oil. The mousse was confined to the first couple of ounces of oil drained, because after that, only black oil came out. <br /><br />I expect the seals need to be changed but I don't want to go there right now. Just wondering how much is too much. I operate in salt water and changing gear lube is something I'll do more frequently now. <br /><br />When you drain the gear lube, do you normally see a little mousse, or none at all?

 

[Xcusme]

Re: How Much Mousse is Too Much?

Mako171,<br />It's not a good thing to have water intrusion into the lower unit. Do a pressure test of the lower unit(submurged in water) to look for leaks. Replace the lube and use new washers/o-rings on the fill and vent screws. Take her for a spin and drop the lube again looking for water in the lube. If you're lucky, it was just bad fill/vent screws washers. If the screws have an unthreaded portion near the head of the screw, use o-rings. If the screw is threaded all the way to the head of the screw, use nylon washers.