Glenn Gardiner says:

Before changing the trucks I would convert to Kadee couplers. The horn and hook can be cut off the trucks and Kadee couplers body mounted to the cars. I am not familiar with the train set you are talking about but this process is quite similar for all rolling stock. I would think your cars have plastic wheels and while doing the coupler conversion is a good time to replace the plastic wheels, with metal (nickel silver wheels.) I use Intermountain wheels and am quite happy with them. There are other manufacturers that sell them, as well. There are online videos that can show you the process. Removing the horn/hook coupler and body mounting the Kadee couplers will convert an otherwise poor performing car into one that performs amazingly well. I have found that the Kadee #148 whisker coupler and the #242 snap-together coupler box, are a great combination. Glenn