Eric,
I actually forgot to ask you if it added more static friction then you cared for. The reason I ask, is you can build up a brand new diff with all new parts and have spent some time doing it and come up with an amazing diff... that might only last a few runs. Adding the thrust bearing will add just a tiny bit of what feels like friction, but it should be barely noticable. Some guys flict their diffs in their fingers and they go SSSSSSSSSSSSSSS for a second or two. My set up less prone to doing that.

Then there some axles, like we just found out about, that have different tollerances then the industry standards I am building the thrusts for. That's why I have that picture showing that .140 measurement. If you have something that is too close to .140, then I need to change something.

Does that help?
bb