replaced impeller, shaft seal, and the white wear ring that goes between the impeller and diffuser. let it all run before putting strainer half back on to make sure no odd noises in the reassembly. All good....
Put all back together... kicked on the hi speed and all was good for about 15 minutes as usual.. then the pressure drops from 18-20 down to 5 and a boatload of racket again. Not really a bearing sound though more like a clatter.

Observation #2, if I cut the valve half closed on the return side to force the pressure to build back up the racket stops. I think the racket is just cavitation do to whatever is causing the pump to not be able to maintain pressure.

Just bizarre, prime side stays full... pressure side drops... due to the time is still sounds like a heat thing with the motor, perhaps not bearings, maybe the motor itself is just doing something odd... it is a two speed emerson/hayward tristar. The motor was replaced once for previous bearing issues, which was a much different noise.

Are they clutched or anything where it would run on high but something slows the shaft... just stabbing in the dark...