REAR DISK BRAKES HUMMING

Sounds like the same set up I used to sell. I was dealer for TSM. Sounds like rotor warped. Not sure what they use now but the last 2 kits I saved for personal use has FORD rotors machined for 8 3/4 Dana 60 fit.
Yea im not sure what the rotors are. I only know what the calipers & pads are from. I contacted them not to long after i bought them because the one piston wouldnt turn in. I wanted to know what the calipers were from. They told me they were a 1980s caddy