i took the wheels off today to paint my calipers and i noticed what looks to be a grease fitting on the passenger side of the rear axle housing leaking. it appeared to have leaked at one time or another but im sure if it currently is. the grease ,or whatever it was, was wet. i tried to tighten the cap that covered it but it wouldnt tighten. it also wouldnt come off either.
what is it?
View attachment 310011
what is it?
View attachment 310011