I just fixed my Bissell vacuum. It was super loud also. I had to get a new brush roller. An easy way to test it is to remove the belt and run the vacuum, if it sounds fine with the belt off replace the roller brush and the belt while you're at it.
Thanks Blondejon I tried your trick and it did not work for me
Unfortunately the motor cannot be opened, it is pressed together so I could not change the bearings and the small brushes look good, so I have ordered a new motor, brush & belt. That should do the trick.
The main thing I have learned is to keep the filters really clean. I could really see the dirt and cat hair inside the motor so I know that did not help matters.
Now I know what to look for next time.
This thing better last now or else!!!!!