>:( I have a set of Spectrum passenger cars. The kind where the coupler boxes turn with the trucks via linkage inside. Problem is the coupler boxes sag and the cars come uncoupled at various times what can be done to correct this?
They are a bit saggy. To tighten up the coupler box, I've put a shim on the frame just above the inside half of the coupler box. Or you can put a shim in the coupler box, just below the coupler shank. A very thin piece of plastic is sufficient--too thick and you'll restrict coupler movement.
Also, trackwork matters. I can't run the passenger cars on our club's modular layout because the trackwork is too irregular. They run fine on my home layout where the trackwork is smoother.
I never found a way to tighten up the linkage on inside mechanics you mentioned.
Kadee couplers have a thicker shank than the EZMates. That helps the sagging a little, too. Good luck.
Regards,
Jonathan