[Closed] SRAM MTH-746 hubs

Has anybody found a way (better bearing perhaps) of making the bearings last longer in these rear hubs or are they just a dead loss? I've had the bearings replaced several times by the LBS and yet roughly every 150-200 miles the wheel develops play which will only go away once the bearings are too tight and so the bearings need replacing again. Muddier and rockier rides seem to hasten the demise of the bearings.

They are now out of warranty and I'm going to have to do the bearings myself which I don't mind doing but at the rate they seem to wear it will be cheaper to buy new wheels. Never had this problem with any other hubs.