I have a Lionel Scout, which is a 2-4-2 engine. The rear two wheels seem to bounce around alot when the engine runs, and when you try to back it up over a switch or any other device that doesn't have totally smooth continuous rails, those rear wheels want to bounce up and derail. This is true whether it is hooked to the tender or not.
In seeing this, I thought: "Well, there must be a spring on that coupler arm that forces the truck down onto the rails, which has grown weak and has worn out."
To my surprise, a there is a flat spring on the bottom of the coupler arm, that pushes down onto a little flat bar, and forces the rear truck Upward instead of downward. No wonder those wheel want to jump up and derail whenever the engine crosses uneven surfaces.
Why in the world did they put this flat spring in like this? It seems to serve no useful purpose?
I am thinking of drilling out the rivet that holds that flat spring to the underside of the arm, and trying to install it on top of the arms, so the rear wheels are forced downward.
Any insight or analysis is welcome.