I have found the green Merc oil to be pretty much $hit in my SSM drives.
Everytime I get a drive back rebuilt (always with green stuff) after 10 hrs it starts to expand into my expansion bottles. Drain it and it comes out water thin.
I don`t like that stuff at all.

Severe gear never expands/aerates like that .

As in Amsoil Severe Gear?

I had same experience in #6's - $hit comes out like water. I went to Severe Gear.

so how well does the green stuff have to be flushed out to change to the yellow? drain and fill or more or less flush as much out as possible?

I have drain out the green oil from bew drive over the winter and mount also clean new lower.
In 10 hours after first change i can tell what colour comes out.I think first 1-2 oilchanges it was a bit green but i will see.
Michael

Oops wrong thread. Sorry.