Bad quality ball bearings on DEX410R??

[muratti]

I recently had my second run on my DEX410R and it performed awesome! Only bad thing is that after about 10 minutes of driving both ball bearings on the left rear axles were completely worn. Balls were all gone and only the rings were left. I wonder if anybody had this experience? Is it possible that Durango used cheaper bearings on the "R" than on the normal DEX410? Just a thought.
Let me know your experiences.