(EDIT: looking at the pics again I think it might be the outer boot at the very top of the inside that has a small hole...I felt around the boot but probably didn't touch that spot) 2007 PRIUS - 350K miles I still haven't taken my passenger-side wheel bearing apart and re-installed the dust cover for the brakes. I went to look at how it was doing and noticed heavy-grease all over inside of the wheel and some of the suspension components. I replaced the passenger-side axle and that seems OK but there is heavy grease everywhere. Gotta put it off til' tomorrow but curious what to even look for? OR is it the shock-absorber that has broken from the top and shock-grease is coming down onto the wheel from the shock-absorber? seems more likely because its falling down on the suspension but not sure what shock-grease looks like. It's dark outside now but at sunset I checked underneath my car and took a few pictures.