Need help with 2-4-2 Loco

[Jim511]

I recently acquired a Prairie Flyer set with a 2-4-2 "Old Timer" Locomotive. Set the track up under the tree, put the Loco on the track and it gets power, but doesn't move under its own power like it should. It "bangs" and skips.  

Took the lower chassis apart and on the rear drive wheels, there is a gear on a serrated axle shaft. The gear has a split in it between two teeth, and it doesn't grip on the axle like I feel it should. The Gear can also slide completely off of the serrated section.  I'm assuming this isn't how it should be and is the route of my problems? If so, does anyone know part numbers or parts I can use to fix this? Thanks

https://photos.app.goo.gl/99GdBcRHChJYGCjUA
https://photos.app.goo.gl/yJR1C6QWhhN1caSP6
https://photos.app.goo.gl/LG2o8w2HBV2Lzczf8
https://photos.app.goo.gl/rmKc3L9wYyDq9udq5

[Loco Bill Canelos]

Unfortunately Bachmann does not have the part you need.   NWSL.com is back in business and perhaps you can see if they can help.

Loco Bill

[Joe Zullo]

Unfortunately Bachmann does not have the part you need.   NWSL.com is back in business and perhaps you can see if they can help.

Loco Bill

Jim and Bill,

I had the same problem with this one donated to our train club.

Bachmann Columbia type

This loco was LNIB, but the same gear was split (very common problem with older Bachmann locos).

Can you 3 D print?
I printed a gear using PETG filament that worked for a while ( until a different gear split).
I can send you the STL file if you are interested.