Our pool pump has become very loud in the last month or two.  The guy that cleans the pool told us that we need to replace the whole thing because the bearings are probably going bad.  But every description of bad bearings includes "high pitched screeching".  Ours is not making a high pitched noise.  It is just a much much louder version of the normal pool pump sound.  After listening to it closely, it sounds like it is coming from the back part (motor).  I'm thinking we only need to replace the motor (AOSmith M48AA66D58). Which motors would work as replacements? Any help would be greatly appreciated..