Thanks for the ideas. I do want to try and listen myself to confirm. The shop - who supposedly has done many MB driveshafts and center bearings, had it on a lift and said the driveshaft was ok. They were under the car while the driveline was spinning and said there was "noise" coming from the differential, which lead to their conclusion. They felt the axles were ok now as well.

I have some records from the previous 210K miles, but none that specifically say the rear end fluid was changed. I had it changed when I got it 2 years ago. The shop yesterday said it was full and the fluid was clean in their determination. They didn't pull the cover or do an extensive check for metal parts floating.

The only suspect thing I can think of is I did bottom out a year ago on a sandy road down at the beach. I wonder if sand got into/at the pinion bearing and caused wear. I'll get under it this weekend and explore.

I have located a used center section for a "reasonable" price, so there is an option to replace it without going broke.

Film at 11, probably an update early next week.

Chuck