American Flyer 9900 Burlington Zephyr

Not sure what exactly you are asking. 

The wheels should have a wrap around steel rim and a gear cast on the back.  There should be a pinion gear attached to the armature shaft, which turns an idler gear that touches both geared wheels.

Sorry , wondering if the gears on the wheels go all the way to the wheel ends or are they recessed in a little.

They were recessed in a little and cast to the inside of the flange. Not including the rim the wheels and gears were a one piece casting.

Thanks..Was this to allow them to run on 0 -27 track and switches?

@Dennis Pateras posted:

Thanks..Was this to allow them to run on 0 -27 track and switches?

American Flyer O Gauge  used 40 in curves but were able to run on Lionel 031 Curves. I don't think they would work on 027 but never tried.

Thanks I was wondering about the radius thing too.