I removed the unit and removed the screws on the back side of the blower housing however it will not separate. I believe the halves may be glued together. The motor has in/out play on the shaft but no noticeable lateral play. I believe the blower must be replaced as a complete unit. I found what looks like the unit at www.americanhvacparts.com
and it is called "Inducer blower motor" and the motor and blower are together as a single unit.
Since the cost of this unit is $267 I am wondering if anyone has had the same problem and if the unit needs to be replaced soon.
Thanks for the help so far!