When I first picked up the plane I noticed that the prop seemed to be spitting a small amount of grease which I noticed on the windshield. I was told that some was normal (didn't seem so to me), so I let it go.
It seemed to go away for a while, but it seemed to come back a few weeks ago, so I investigated and it turns out it's not normal and there's an Airmaster Service Bulletin, SB-18, that addresses this exact issue.
So, I started on this work tonight.