8 3/4 diff

That there is the whole reason that I and cosgig (probably) prefer to stay away from crush sleeves. If you need to replace the pinion seal or remove the yoke for some reason, you have the chance of messing up the pinion depth. Changing the seal can be done without changing the pinion depth if you are careful, but often people aren't.

gunmetal72 - If you have the 489 case in your car (this doesn't apply to 741 or 742 cases!), and he changed the yoke without worrying about how far to crank it down, you likely have the pinion setting messed up. You will have to remove the entire pumpkin and take it to a good differential mechanic to get it re-built. When he rebuilds it, make sure he uses the hard spacer that replaces the crush sleeve so you can swap yokes again or fix a seal in the future without worry. Either that, or replace it with a used 742 or 741 gearset (probably cheaper - but you will need a different yoke).