Yeah, it probably is the rear bearing, and there are several thoughts here.
Having wrestled a few of these machines, and given their other problems my advice is to replace it, but given that yours is an expensive stacked machine and replacing it means a new washer and dryer, or combo, you may want to think about a repair.
Here is a set of posts which describe the process. Yes, it is a lot of work, most of it hard and frustrating, and no I don't recommend it unless you are really skilled at tools and repair but if you want to give it a shot these posts will take you through the process.
Neptune Bearing Repair - Pic Tutorial