Crankshaft alignment ("run-out")

Section E-40 of the FSM explains how to check the "crankshaft alignment." I followed the directions but I'm not exactly sure what it is proving or disproving. I started with the center journal as explained and put a dial indicator on it, spun the crank and noticed that the needle moved .001". I then did the front and then the back as explained. They both moved .002". The FSM says the "maximum allowable run-out is .002". But what does this mean? Does it mean I'm in spec or did I misunderstand the instructions? I'm not concerned about it, I'm merely curious.

 

You are basically checking to see if the centerline of your crank journals are straight, they all run on the same centerline.. Also if the journals are round as a byproduct, but the intent is looking for a bent crank.. And yeah, at .002, you are fine..

Bubba