The electrocouplers on my Erie Mining Legacy C-420 do not want to close. I have to back the loco into a string of cars at Legacy railroad speed 3 (medium) to even have a chance of the loco's coupler closing. Even then it doesn't always close. With other locos, I can hit the cars at speed 1 or 2 or very gently back them into a bumper, etc. Feels like something is wrong with these couplers. Is there anything I can do to get them to close a little easier or should I just replace them?