I agree with James, at some point the bearings were run while too loose or too tight.
Manuals say to tighten them to about 30lbs.ft. while spinning them, and then after loosening them, tighten to about one pound foot. For different vehicles, it may be different, but basically in a range of about 120-150 inchpounds. Using a 1/2" ratchet, that amounts to not much more than the weight of the ratchet itself. You can tighten the bearings tighter by hand than they should be.
New bearings often need to be retightened after being driven for some miles. When tightened, the tire should spin easily, but not continue to spin for a long long time. There should be no large amount of play of the tire. When assembled, pull the top of the tire out, and push the bottom of the tire in. Alternating pressure to check play top to bottom should reveal very little movement. That is a check which should be done at any time that the tire is off of the ground. Good luck,
