How to I replace the truck on GP 40 BSNF 3100 locomotive?
Have you looked in the Information Page at how the trucks are part of the loco? The page has helped me a few times.
Rich
https://www.bachmanntrains.com/home-usa/board/index.php/topic,36963.0.html
This may help.
If you have the most recent version of the GP40, the trucks are identical to the F7. The link will show a few pictures of my F7 project.
In a nutshell, there is a small screw at the top of the truck. Remove that screw and the truck will drop out. BE CAREFUL. There is a drive axle between the fllywheel and the truck. It can get away from you.
ALSO! There should be 2 wires that are connected, with press tabs, to the PCB. Loosen those wires BEFORE you drop the truck.
Hope that helps.
Regards,
Jonathan
Thank you!