You should check the jounce and rebound of each corner of the vehicle. Go to one corner and get the vehicle rocking up and down. It should be fairly hard to get it to move. When you get it bouncing fairly well stop and see how many times it continues to bounce. Should be only one or so. I had one go bad and you could get the whole front end bouncing on one side, but the opposite side you could hardly move. Also look for any signs of oil leaking near the shock.