03-04-2009, 08:31 AM
If you are running the stock couplers from Athearn, they have the plastic knuckle spring. These will take a set over time and lose tension allowing the coupler to open under load. Replace the couplers with Kaddee and you problem with uncoupling should be solved if your track is level enough. I think Kaddee now offers a "tight lock" version of their couplers, and I've heard they are a bit harder to uncouple, but are almost immune to nuisance uncoupling problems.