Coligion wrote:The Dreamcast has a small ball that allows the d-pad to pivot on.
That is the d-pad.
As for the looseness, I would say that it might not have been put together correctly after the cleaning. Grease/lub is not necessary.
Was it loose before you took it apart?
These controllers are only slightly tricky, due to the two extra screws that hold the pcb (inner board) to the front of the controller by the plastic vmu-input holding carriage. Can you verify that this was put together correctly?
That plastic carriage does have grooves that align and hold the pcb (the inner board) perfectly in place, and if it is not in the groves, it might be holding the board back enough to cause looseness.
Other than general assembly, you might want to check and see if the rubber pads that go between the actual d-pad plastic part and the pcb (the board), is aligned correctly as well. It does have encompassing ridges, and if it is not placed in correctly it again might push the board back just enough to cause that plastic bit to wiggle.
Lastly it might be that the screws / seams of the controller are not correctly touching. Just look along the two shell parts and see if there are any gaps, that you might be able to squeeze together ("pop" it together), or if the controller cord might be in a position where the plastic shell is not being allowed to connect properly. Even if you start screwing it together, the screw might feel tight, even if the plastic shell still has something stopping it from connecting.
If all else fails... These things are what, ~$4 new? Just get a new one. If you have a colored shell, then you can just switch the shell parts on to the new controller. I have a few fun examples I could share, but villagephotos seems to be unavailable at the moment.