When driving over very rough spots, I hear a clunking noise coming from the left front. (Driver's side - US car). The road has to be very rough; it doesn't do it very often. I don't feel anything moving. When I steer quickly left, right, left I hear nothing. I replaced the lower ball joints about a year ago. They were emitting more of a creak. I'm thinking maybe a broken spring? But I'd expect more of a spring noise. This is kind of a deep thunk or clunk. Any suggestions on where I should search? Thanks.