This coupler replacement solved my Problem at least for the Friendship PS-1. I can't seem to find anymore of the same part number, but there are others that will likely do the job. The Lionel part number is 6-12843. These coupler/trucks are very heavy (in a good way) and come with screws which are slightly longer than the crappy couplers due to the screw hole being much thicker die-cast. Where the screw goes is the actual part of the truck that is "Sprung" and they are strong springs. The PS-1 boxcar tracks very smoothly and the coupler action is perfect.
Photo #1 - unboxing the new coupler/trucks
Photo #2 - The underside of the new coupler
Photo #3 - The other side
Photo #4 - A Side shot of the springs
Video #1 - The smooth glide along the track (aided by the truck heft)
Video #2 - The all important coupler mating
Photo # 5 - Side shot of the attached new coupler on the PS-1