Wheel noise, bad wheel bearing? Video included

I have a strange sound coming from the rear of my truck. I hear it more on the drivers side. I normally would assume this is the wheel bearing going bad. But the guy I bought the truck from told me he just replaced both rear wheel bearings and brake shoes and gave me a receipt of it. They were installed 3 months ago. It wasn't as loud when I bought it so I thought it was the tires, but it has got louder here lately. In the video you can see where the assembly has fresh surface rust on it like they have just been replaced. Any ideas? https://www.youtube.com/watch?v=sgCfvTRsusw

 

That doesn't sound like a bearing that sounds lke something wasn't put back together right in the brakes. Does the sound come from one side or both?

 

Brake shoe installed wrong or emergency brake

 

The driver side for sure. But it thumps so loud its hard to tell, the passenger side may be doing it too.

 

I would suggest taking off the wheel and drum, then spin it back up again and listen. CAUTION!!! DO NOT APPLY THE BRAKES WITH THE DRUM OFF! Just let it slow down naturally, and turn off the engine until it comes to a stop.

 

Ill try again with the drum off. But I'll add that my brakes/parking brake work fine. The sound does not stop when I apply the brakes. A mechanic said it sounds like a bad rear end. But he just drove it and didn't put it on a lift.