Left rear caliper grinding against rotor ????

About 2 weeks ago I noticed a rubbing/scuffing sound coming from the rear. Didn't really know what it was and couldn't see anything from the wheel. We had weather in the teens and some snow, but anyway know place to work on the car in warm climate. Also a popping sound from the left rear/drivers side rear when backing up sharply. The other day I finally noticed the caliper is grinding against the driver side rear rotor. The only thing out of the norm I did was turning in a cramped parking lot the right front tire went up on a curb slightly. Nothing else out of the norm. Due to the cold weather and summer tires not working so well. I haven't even gotten the car past 3500 rpms in months. No burnouts or anything.

So what happened. Anyone have any ideas? The popping and the caliper grinding on the rotor? Almost sounds like 2 problems.

Thanks
Josh

Appreciate it yall. I'll look more into it to see whats going on. I've already trashed the rotor which isn't a big deal. I got a good guy thats done alot of work on 8.8 differentials. So I'll get him into looking at it.

This is just an update. I had the car fixed but delays with the Snow Storm that hit the east side of the country. The caliper bracket was frozen. That was the issue. Went ahead and had the shop put in break pads and resruface rotors. The C-Clip and Axles were fine. Guess it was just one of those rare things that happen.

Josh