Hello again.
Back on the first day of this month, I posted that I was probably done with this thread "until something else breaks and I need help again". Guess what? 
This has been running beautifully; except every now and then it'll seize up and stop. I had it apart (again) this morning: the motor/driveline checks out OK, and the chassis sans motor rolls free and easy. If I attach the motor/driveline, it'll run fine up on blocks, but once it's on the rails and has to propel itself, it will freeze up again.
I think the problem has to do with the center geared drivers. There is a little "play" in the front and rear set, and if I move the center set on the engineer side, it is the same. On the fireman's (left) side, there is none of that play; I think my issue is that one of these drivers (probably this one) is not "seated" properly on the axle. I'm guessing I'm going to have to drop that axle assembly out of the chassis and re-do the driver/axle connection.
I did not do the initial building of this engine, and don't really know how it was supposed to be assembled, or what to look for, so fixing it might prove to be bit of a challenge. Any ideas/suggestions would be greatly appreciated.
Thanks yet again. 
Mark in Oregon
