[Tim Brewer]

By "wiggle", I mean you should grab each of the four rods and be able to fairly eaisley twist them by moving the rod ends. If any one of them (with weight on the wheels) can't be twisted, it's bound up and needs to be adjusted. The squeeking could be one or more of thr rods being bound up. Don't forget to grease them, but like Fred says, they are of low quality.
Tim