Disassembled washer, found that 2 out of the 3 basket support legs had cracked through. Unfortunately, support cannot be bought except as an assembly, so had to spend almost $300 for the part. Bearings were worn, but not trashed, so I replaced them and the seal. Note, most parts places (including AppliancePartsPros.com) will only sell the bearings and seal as part of the rear tub assembly. The bearings are standard 6205 and 6206 sealed ball bearings, available from Grainger and many others for $8-$12 each. The shaft seal is a little tougher - there are some online stores that sell them if you hunt.
Everything went back together reasonably well. Washer is working fine now. Hardest part of the process is getting the spring clamp on the bellows reinstalled.