I have a '97 F 250 HD, and the tailgate rattles as I go down the road. Does anybody know what wears out or what is adjustable to fix this? It still has the plastic "cup" at each pivot point, and the rubbers look to be in good shape. Just wondering if this is a common problem with a common fix or what?

 

Do the little bumpers at top contact the gate? I mean when it's up can you shake it and feel the movement?