a/c clutch or compressor
 

My a/c compressor is making a knocking sound at start up. I turn on a/c then it turns to more of a squealing noise. I have a new belt installed. When she warms up for about 15 mins it goes away. A/c works good gets really cold no problems in the cab. Just that noise. Would that be just the clutch going out or the whole compressor. Thanks guys! One more thing when I had the belt off I spun the a/c compressor it did rub a little(hit and miss) I sprayed wd and it got better but not completely. Thanks again!

Just in case anyone has same problems. End up being the bearings. Replaced pulley witch comes with bearing and clutch. She's all good to go once again.