JD 730 moco bearing

Bottom right conditioning roll bearing keeps going out. Seems to last only 1 or 2 seasons before it needs to be replaced again. First time was replaced under warranty by JD tech. On my 4th one now and it feels like there is a little play in it again. Roller spacing, timing, and pressure seem good. No problems with other three roll bearings.

Anybody have any ideas of a problem to look for? Or something I could do to make bearing last?
Any help will be much appreciated. Thanks.

JD 730 moco bearing