I changed my rear end chunk from a limited slip into a possitve traction now it's making a humming noise I'm trying to see if it might be my pinion gear bearing or what because I don't want to tear it up anymore

My driver's side rear tire sounds like it's grinding rocks, and makes a very weird KKKKKKK sound anytime I am driving slow...and I have brand new breaks. It's driving me insane! NO mechanic can figure it out! And just to put it out there, I do not, nor have I ever had an Emergency Brake the entire time I have owned my truck since I bought it in 2013.