Wheel Dollies

Can anyone clue me in on what I may have done wrong here.

I picked up 4 of these ( similar style ) wheel dollies http://s675.photobucket.com/user/jhason2/media/wheeldollies_zpse491848a.jpg.html from a place I was working at that was going to toss them cause they were abused badly and the wheels themselves were all messed up.

I cut off the remains of what was left of the casters and bought 16 of these wheels ( similar style ) http://s675.photobucket.com/user/jhason2/media/medium-duty-dolly-casters_zps87c10f22.jpg.html from Harbor freight.

I did not get the cheapest I could find. I bough the heaviest 4 or 5 inch wheels they had rated for the heaviest load. They all swivel 360 degrees. They were rated at something like 400 pounds a piece.

When I put a car on top of them and try to move it the individual casters on each dolly just work against each other, one will turn one way and the other just wont turn at all ect. They just bind against each other. The car just will not budge without alot of brute strength ( AKA a big fat *** ) pushing against it hard.

Looking at pictures on-line of wheel dollies it seems like using wheels that rotate 360 degrees is just fine, is this just a case of cheap casters that need to go or should I be using two stationary and two swivel per dolly? That dosent seem to make much sense to me though.