I have a Fanuc 18i Controlled cnc.. There is loud noise on x-axis.. So I disassambled x axis supporting bearings. There are two bearings on each side.. i will buy new ones. But is there any side of the bearings by installation, also someone told me to make 0.15mm force on the bearing by installation. I don't know what he means ... Pls help me about replacing of supporting bearings.