A common question we get asked is "Can you change standard OO couplers to Kadee knuckle couplers?". It can be done on newer OO scale locomotives & rolling stock with a few exceptions. Pre NEM stock can't be converted as easily and requires a certain amount of DIY modification to change the couplings.
How to change your couplings
Changing couplers on newer OO scale locomotive is relatively straight forward, providing it is a newer loco with a NEM socket. Here we will be using a Bachmann Branchline L&YR 2-4-2 Tank Locomotive and a #18 Kadee coupling.
Removing The Coupling
Removing the coupling is very simple. Flip the locomotive upside down and hold firmly by the body (be careful of the finer details on the loco), hold the coupling on either side and pull firmly.
The coupling should pop straight out leaving the NEM pocket ready for a Kadee coupling. As you can see below, both couplings have the same barbs for direct change into the loco.
Installing The New Coupling
Installing the new Kadee coupling is as easy as removing the old one. Holding the loco firmly upside down, line up the new Kadee coupling with the NEM box. You will need to squeeze the barbs together to fit them into the box.
Once lined up and the barbs have been squeezed into the end of the socket, give a small push and you'll feel the coupling click into its location.
That's it! Your new Kadee knuckle coupling has been installed. Whilst knuckle couplings on British locomotives aren't 'correct' to the real thing, they do look better than standard OO couplings and this gives the opportunity to run OO scale stock with HO scale stock.