I would agree it's important to do... I've shimmed diffs to prevent the crown wheel rubbing on the case and tighten the gear mesh. Since doing that I've noticed that I have reduced the number of damaged 13t bevel gears.
My thoughts are that going to an alloy diff housing (like the one in the links) will do a lot to help save 13tbevel gears as well.
They are a particular species of bear with a flat angles forehead. They were common around Knox until savage owners found out that their heads make great jump ramps and so starting seeking them out. Of course if the savvy driver got the landing wrong then the bear would be wrecked and so he would have to find another one. It's sad to say that use savvy drivers have almost driven the bevel bear into extinction.
Do the shims go on the inside between the cup/pinion and the bearing OR on the outside between the bearing and the diif shaft? Does anyone do a shim kit? Is it necessary to do it to the 13T as well? </font>