On my T4 I didn't have any blown bearing issues.
How dirty is the area you are running? Maybe you got a bad set of bearings?
You may want to just get into the habbit of cleaning the bearings. Since they are the wheel ones, it shouldn't be too bad to just pop them out. Put them to soak in some motor spray, reoil them and re-install. At most this would take about an hour ( soak time included ).