I think your best bet would be to swap out the frame and trucks. You may be able to find what you need on ebay or from Athearn/Roundhouse.
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
Thanks for the tip.
Those roundhouse trucks are diff than a Athearn both internally annd externally. I tried to substitue athearn idler gears but no luck. Hope to get parts at swap meet or Ebay.
This just showed up in my e-mail:
http://www.ebay.com/itm/291524514053
It might be just the ticket for your problem.
Larry
www.llxlocomotives.com
So many trains, so little time,
The only pic I could find on line look like this unit has a blue box type truck. It is possible that the unit had Ernst gears put in the trucks. If that is true, then the axle gears are offset. You can tell that because the truck has more than three gears inside. I have seen several BB drives with these gear systems. The axle gears are almost always cracked. This is typical of the used BB drives I see. More than half will have cracked axle gears. My practice is to replace the Ernst gears for a number of reasons. They are a big drag on the motor. The extra gears and surfaces create a lot of friction. This will require you replace all the gears in the truck. The B-B GP, F unit and u-boat trucks all have the same truck gears, so they are easy to find. This allows you to use the replacement axle gears that are ready available.
Larry,
I've got a older athearn drive Roundhouse RS3 that has some split axle gears (like the earlier proto 2000's). These gears have an offset to one side for the gear box ratio. The trucks have a different pivot setup on the frame than a standard athearn replacement... Has anyone replaced or converted one before? Just trying to get an old favorite back on the tracks.