Wheel bearing or Strut bearing
 

Symptoms: The brake has a 'rub' right on the top, outside edge of the rotor which is shaving the corner off of the rotor. I've noticed an occasional popping from the right front when I make a tight corner turning around in the cul-de-sac.

History: I changed the brakes a couple weeks ago. When I pulled the caliper off, a helicoil fell out of the hole. The thing had been stripped out. There had been a slight issue with rubbing along the top, outside edge of the brake rotor that I (probably wrongly) attributed to the caliper probably being misaligned due to the stripped out hole. I replaced the caliper.

Hub?: Last weekend, I noticed the rub was back. I looked and saw that the corner was being taken off of the rotor. I jacked the car up and yanked on the tire to test to see if the bearing was bad. It was nice and tight. At this point I was stumped.

Strut bearing?: Over this past weekend, I started doing more research. I discovered on other threads here that there is a strut bearing that can go bad. Being a novice, I had never heard of a strut bearing.

Could a bad strut bearing cause my symptoms? What is the most likely issue?

If it is the strut bearing, would I purchase a strut mount kit or just a new bearing?

(Thanks all for your patience, once again, with a novice mechanic :))

The strut bearing is at the top of the strut, attached to the body by the three studs and nuts.

https://www.1aauto.com/chevy-cobalt-...r/i/1asfk01368

your issue seems to be a stripped out calliper mounting thread .
you should replace the steering knuckle itself and the rotors

https://www.gmpartsgiant.com/oem-che...g_knuckle.html

I replaced the caliper which is what had the stripped threads. Do you still think I need to replace the steering knuckle?

I don't understand, could you please post a picture? it's easy, link in my sig.

You mean which bolt hole had the helicoil

A bolt hole in the caliper itself had the helicoil. It received the bolt that ran through through the steering knuckle.

The threaded hole in the calliper brackets, much easier to replace

https://www.autozone.com/brakes-and-.../chevrolet/hhr

Unusual wear along with a noisy rub on Rotor - 45 degree angle wearing away from outside edge.
https://cimg5.ibsrv.net/gimg/www.che...b3292f2e54.jpg
Corner wear like this:
https://cimg7.ibsrv.net/gimg/www.che...5992e29d32.png

That is fixed. I replaced the caliper.

I've never seen anything like that. Something metallic is rubbing it, not pads. Maybe wrong size rotor?
The strut has nothing to do with the caliper to rotor geometry. Hubs cause a lopsided wear pattern on the pads and tires. The inside of the tread gets bumpy from bad bearings