With regards to the operating track section, I'm having a problem: when an MPC GG-1. When the gg1 passes over the track, the trailing truck coupler opens. No matter which direction it's going, the trailing coupler opens. I've not tried another GG-1, basically because I have only one GG1. This does not happen on any other engine that I have. I'm not trying to hijack the thread, I thought it might be helpful with the subject problem.