Hi guys. I believe that the bearings in my A/C compressor clutch are about fried. They make the most obnoxious metal on metal hum/screech I've heard in a while. In an effort to save a little money, I'll just replace the two bearings instead of the whole clutch assembly. Should I have to drain the refrigerant before taking off the clutch to get at the bearings? Also, should I just use any old lithium type grease to lubricate the new bearings?