Good call Stan Pittman!
I ordered a water pump from Fastlane, and started on the job this morning. The water pump was fine, but the fan pulley bearings were gone.
So much for the diagnostic skills of American Service Center.
Located a replacement at a dealer with parts dept open on Saturday (HBL) and installation went without incident. If you do this replacement, you will probably need an updated version of the bolt that holds the fan clutch to the pulley - the new part requires a shorter one. You will also need the O-ring where the heater pipe goes into the thermostat housing.
One tip - you only need to loosen, not remove the small bolt that holds the heater pipe to the top of the bearing housing. Once loosened, you can slide the pipe to the left and proceed with the removal.
This also seems to have cleared up the suspected chain noise.