Growling noise from rear 2002 Dodge

I just bought a used 2002 Dodge Ram 1500 4x4 4.7L V8 and there are a few issues that have come up but nothing as serious as this growling noise coming from the rear brakes or axle when performing a slow stop. It does it right before the truck rocks back after slowing to a stop. I had some issue like this in my old 1997 Chevy C1500 that had 208,800 miles on it and there was a leak in the axle seals. I hope that this isn't the same problem. This used Dodge has 94,885 miles on it and the CarFax checked out but I noticed a little bit of red paint on under parts of the bed which seems like it was involved in some kind of accident because the current color of the truck is blue. Also, the front left brakes are squealing, I've checked the pads, caliper, and rotor and they all checked out. Another thing is when I'm driving on a gravel road or over bumps, there is some noise pretty much right underneath my feet around that sounds like something is loose. Any ideas on what any of these things are?

Grinding noise could be the retaining clips in the rear differential. Those are known to fail. I know know it's been a while since this post, but I hope the gears weren't trashed.