What do you consider "faster than normal"?
How are the tires wearing? If you have abnormal tire wear you will want to have the rear end checked for alignment/damaged parts.
If the issue is simply that the bearings are failing it could be that they are being installed incorrectly, that the bearings are low quality or that the vehicle is overloaded.
Saturday, January 21st, 2017 AT 11:45 AM