I think the same thing may be happening in one of my front struts.A well-written description answered this problem fast!
My right rear strut is doing this, and yes, there is a oil leak in the strut's seal. Springtime project...
You know, I think the leaking strut in my front passenger side might be what's causing the rattle/clunking noise coming from that corner when I go over dips in the road at slower speeds. I might have had my endlinks replaced for nothingYES, more like a light rattle...but I live in Chicago and don't feel like lying on the driveway when it is 10 below outside. Must wait till Springtime.