Wheel brg. failures have been widely reported on Chevy and GMC trucks. It seems like most of the problems are in '05 and later models. Does anybody know exactly what has caused the problem, poor design, manufacturing defect, outsourcing? I have been told GM starting buying bearings/hubs overseas, and quality was bad. No issues yet with my '02 Avalache,, but it has 169,000 miles. Should I be concerned??