I did a search into the birf.com archives and was reading up on how to get my birf and axle seperated and came across a thread where a gentleman suggested replacing the ball bearings in your birfs during a repack with new OEM ones, have any of you guys done this with your worn birfs before putting them back into the truck? I bought two used cores from Spectre and one of them is quite a bit "looser" than the other as far as the cage rolling around in the bell and now i'm wondering if i should give it a try, Brad.