I hadn't seen this before, so I thought I would share. An N plate Fiesta came in the other day with a clonk every time she went over a speed hump. I rapidly established that it came from the right hand front, it sounded a bit like the bumper flapping up and down, or as I suspected the bottom arm flailing around. An inspection showed that the rear bushes on the front arms were pretty manky, but the arm wasn't actually flapping about. I then noticed the spring, it was over the edge of the spring cup and had been riding past the cup and back again, I welded a couple of retainers onto the spring cup and re-tested it, the noise had gone !!
Mrcheerful