Product review (5 stars): You will want to replace this if you are replacing the tub bearings
I went with the option of buying the rear tub with bearings and seal rather than trying to replace the bearings in the existing tub.  I'm glad I also got the drum shaft too! You would be shocked at how much gunk and crud was built up on this part. The tub itself was pretty dirty too, but this part you would have a hard time cleaning.  This is also where the bearings ride and if they were going out, there is most likely some damage there as I found.  The stainless drum was pretty dirty too on the outside... It did clean up well though and with the new flange and rear tub, the washer is back to working like new without the loud bearing noise on the spin cycle.