e39 wheel bearings

[bmwbmwbmw]

hi guys, on my e39 the p/s/r wheel bearing has gone for the third time in one year, in the time i have owned this lovely chariot i seem to be changing just the wheel bearing, what could be causing this problem, ive checked everything to do with that sides it looks all in tacked, i have taken the car to my local garage and the cant seem to find anything wrong with that side, so why is this wheel bearing keep going

the first wheel bearing was purchased from euro car parts, so i thought it might have been a cheep quality item, the second was purchased directly from company, and the third was a replacement from the company for the second one, i no direct company will not sell cheap quality parts, so the part it self is not an issue

whats could be causing the bearing to die........................