Are you referring to the 3 blade, 60 inch, white fan, HD number 526-012 discussed in
THIS THREAD?
Sorry, cannot help you, I threw the down rods that came with it in the scrap bin and made new ones, 4 ft long, from galvanized ¾ water pipe drilled for the cross pin and drilled and threaded for the ground pigtail and drilled at the bottom for the fan mount bolt and the ground wire.. Mine run smooth and quiet.
Are you referring to the downrod being loose or wobbling in the white ball it mounts into? Do you have the ball correctly seated in the ceiling bracket with the slot in the ball indexed onto the tang in the bracket (for anti rotation?)
Along with the cross pin, there is a screw securing the ball to the downrod, is it installed and tight?
Try numbering the blades and then swapping two of them, if needed, another two. That may help resolve the balance problem. Make sure the blades are properly tightened to the hub.
Charles