Thanks!  That did the trick.  That  locomotive is running smoothly now!
I have another question, and didn't want to open a new thread. 

I also just unwrapped a Santa Fe 212 engine.  I noticed that the gears don't move in any position, by hand or on track.  I've taken the armature out and it is filled with gunk. Tried cleaning as best I can.  When the armature is out the gears on the truck turn fine by hand, but once I put the armature back in, the gears won't budge.  (I also have a trolley that is in the same situation, where it hardly moves by hand).
 It sems to be the gear bolt that comes through the armature itself that is causing the lockup(first pic). 
Or I could be wrong as I am new to all this and am trying to learn as much as I can.  Any advice for getting the 212 to run turn freely?  Attached are some pics of the armature and from underneath as well as what I have running so far.