whining rear

...............did u rotate the pinion by hand b4 and after seal installation,was it harder to turn after...could have a bad pinion bearing, but usually they make a whirling noise, more than likely the gears whined b4 u got them as they usually have .020 bl or more when i find the used.....when u set up the lash tighter they whine like crazy.........this finding is from more than 30 used sets over the years....whomever sold them 2 u likely set them tighter.....kim.......