I dont know the nomenclature for front and back..but only know them as
thrust side and the other side G and the thrust side (often plainly
marked as such) need to be on the outside of the bearing stack, and
pulled together, then the entire bearing group held tightly in the
housing. Ball screw thrust bearing (double bearing) packs have a
removable "cover" that is held in place by bolts/screws that keep the
outer races held rigidly in place.often with a very thin spacer that
contacts only the facing faces G of the outer race.


A simple way to identify face and back is to think of the bearing as a
baseball cap. Look at the Koyo site posted earlier (
http://www.koyousa.com/KoyoCatalog/C...&c=020-020-010 )
and consider the ball to be a head and the outer race to be a baseball
cap. In this case, it appears that the bill of the baseball caps are
facing away from each other and the "back" of the heads are together.
This would be back to back mounting.