Loud, wah, wah, squeal in rear!

I just got my car back from the dealership, someone had hit me in the rear passenger side quater panel. The axle, rear end housing, and wheel had to be replaced. Now, I am getting a loud wah, wah,wah, squeal noise coming from the rear end. I am thinking something needs to be greased but, I don't know what, could you guys give me some insight. I just regreased the slide pins on the brake calipers, no go, still loud sound. Oh it happens when I go 10 mph or slower. Help, please, sound is annoying the heck out of me!

Don't even respond to this thread, thanks for the quick response, its a warped rotor!