How can you get Bachmann gearbox gears without buying the complete motor/gearbox assembly?
You didn't say what gears or what locomotive so it is hard to help.
Sometimes you can get them from Bachmann if they have a parts loco available or a gear they stock.
Some are available from NWSL. Google "NWSL gears"
The loco is a 2-6-0 spectrum. I thought I had a bad axle gear so I followed your article and ordered a replacement gear. When I opened the gearbox the center double gear was stripped. Bachmann says they don't sell the individual gears. You have to purchase the complete motor/gearbox assembly. That's ok, but did they improve the gears or are they just going to fail again.
I don't work for Bachmann so it will be up to them to answer if the gear box is improved. My guess is it is original.
I forgot that the 2-6-0 at 12 years old is getting long in the tooth for a model train locomotive, mine ran for 11 years before I lost the axle gear. Parts are going to get even harder to get as most manufacturers do not make more parts when they run out. It might not hurt to get the gearbox and the motor for $40 while they still have stock. If you do, you could disassemble the gearbox and use epoxy putty to reinforce the drive gear before putting the loco back together.
You can call NWSL on Monday and see what they can do. Their site is http://www.nwsl.com/
They have a gear request form you can fill out so they can try to help you. If you call in person have the info from the form ready as you will need it to get help.
Sorry I can't be more help.
Thank you for your help. I already tried the NWSL site and they were unable to help. I'll order the assembly and hope it holds up. Thanks again for your help.