A little follow up on Steve's explanation and this is just general bearing information for people that may not know. If you do not have a good bearing fit (or you lose oil flow to a bearing) there is a chance that the bearing can actually spin on the shaft that it is fitted on. This will destroy a bearing and shaft in very short order. In industrial type applications the bearing is the cheap part
to repair. I have seen it a couple/few times over the course of my career.