I had a similar problem and Dexter replaced my entire axle assy. Here is a picture of the spindle on one of the damaged axles: The difference in mine was the damage was at the top of the spindle, not the bottom as one would expect.
There was no apparent damage to either the inner or outer bearing or their respective races. It was almost as if a damaged spindle was rotated 90 degrees and welded into a new axle.
Here is a picture of the brand new axle, you can clearly see that the axle is of poor quality and poorly machined at the outer bearing race area.
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There was in my opinion insufficient grease in the hub on the original axles from the factory. There is the possibility that the spindle nut was too tight causing the race to turn rather than the bearing, who knows I just hope the new ones don't do the same thing.