Well I finally got around to a deeper investigation of the breaks. I found this on the bearing on the inside of the knuckle:


The bearing is seized. It looks like there was either some rubbing or something got in there to cause some rubbing. I took the bearing on the outside of the knuckle out of the wheel, and found it's pretty much seized as well. So I've replaced both and put a new end of the driveshaft. We'll see how it works out.