So my pickup has been making a squealing Sound since I bought it about a year ago. I was told it was a pulley so I wasn’t too concerned about it. This weekend my buddy (he’s a GM certified mechanic) and I decided to find out which pulley it was. Took the fan off and the belt to check the pulleys. They were fine. We started the motor with the belt off and the squealing was still there. Its a squeal not a rattle, chirp or tick. Lifting it so we could get under it we discovered the sound appears be coming from the torque converter/ transmission. Of anyone else has had this problem,I would sure appreciate any advice you can give me.