If the suffix is RZ,then it has one rubbing (grease) seal,one tin shield ......if RS,then just one rubbing seal (grease) on one side,other open.Generally , only a 2RS bearing will be "lifetime lubricated",(which works OK in oil,because there is a slight oil leak into the balls as the seals wear)...............as to noise ......sometimes Chinese bearings are noisy,very noisy,especially in electric motors at 3600revs......This does not mean they have failed or run dry,because on inspection ,they are OK ,and have plenty of clean grease.Anyway,make up a driver that puts equal pressure against inner and outer races,or the bearing will brinnel.Avoid driving if possible ,and pull the bearing in ............and rolling element dont need much oil,and flood oiling carries dirt and damaging particles into the balls.....If the balls lock on a piece of foreign matter,the cage may break,causing a true failure where the balls fall out and often get jammed in gear teeth.