wow....this thread almost started a year ago <img src="/forums/images/graemlins/smile.gif" alt="" />

Some heat can be expected......assuming the depth was right then logically that leaves the backlash to think about. If you had unequal tension on the carrier bearings that could cause you grief. That's why I smack the crap out of the bearing caps to allow the carrier bearing races to "self center" (equalize). If this is not done, I suppose the BL could close up some with use.
If you find that the pinion bearings appear to be already worn....or loose....or some heat or blueing action on the races then maybe they somehow ended up to tight or oil is not getting up to the outer pinion bearing for some reason.