I am new to N scale. Where can I get instructions on how to fix or replace a coupler?
Which couplers are they? Rapido or knuckle?
They are all stock Bachmann, I assume Rapido couplers on freight cars. On one, the coupler box is still attached with the spring still in place.
Providing your rolling stock and locomotives are under 12 years old, the couplers are retained by a small plastic clip on the underside of the coupler box. Simply pry the clip loose carefully with a small flat blade screwdriver. It will pop off revealing the four tabs that fit the slotted retainer pockets. You will note the coupler (dummy knuckle or older rapido) is inside the pocket held with a coil spring. Bachmann sells dummy (non operating) knuckle, older rapido, and newer Bachmann operating knuckle couplers. Any of these can be used to replace the existing coupler. Simply fit the coupler into the pocket with the coiled spring and pop the plastic retainer back on. I usually first remove the wheel set nearest the coupler to do this, then reinstall it after the coupler conversion. You can also unscrew the small phillips screw holding the wheel set for convenience. I have replaced the couplers on all of my older rapido coupler Bachmann rolling stock and locomotives with dummy knuckle couplers. Now I am considering the new Bachmann operating couplers. Bachmann also offers operating coupler conversions with replacement freight car trucks. However with these you will need to reinstall the wheel set (wheels with axle). I can recommend ordering from Bachmann parts, or from Trainworld if your hobby dealer does not have the desired Bachmann coupler. Note that either the dummy knuckle or operating knuckle coupler will couple to Microtrains, Atlas, Athearn, or most other N scale rolling stock or locomotives. However, Bachmann knuckle couplers will not fit with Kato couplers since Kato is smaller (true N scale) and Bachmann couplers are slightly oversized, even bigger than Microtrains, Accumate or McHenry. At least this is my personal experience from actually using various brands of N scale including Bachmann.
Thank You! That is the information I needed.