Lionel CSX 21” office car set

add some light oil?

Found the problem. Some of the cars have diaphragms on the ends and some don’t. Not sure of the reason. I had 2 cars with the diaphragms together and they were binding together. Separated the diaphragms and all seems good. One car the coupler opens up but I put it on the end. So far so good

Jeff gibs posted:

Some of the cars have diaphragms on the ends and some don’t.

I think that you will find that they ALL have a type of diaphragm on each end. From the photos that I have seen, three different types have been applied to the cars. Some cars coming with a different type on either end. But, there is a diaphragm on there. 
A photo would be of immense help.

Here are some pics

Put the 2 bigger diaphragms together and they bind up and jump the track

Those "rubber" tubes are the latest style of so called "diaphragm" used on many of the old passenger cars today. I wonder why one is blue and the other black?

Below is an example of a full width diaphragm.

Then you have the normal diaphragm.

The couplers could be beginning to bend upward as you run the cars.  The post fastened to the kinematic plate begins to bend under the weight of the cars.  The passenger cars a much heavier than the Auto Carriers and 86' Box Cars.  The passenger cars have a thick steel plate with detailed parts screwed to it.

All of my passenger car couplers are starting to bend upward.  (SP and UP sets, and Amtrak Dining Car)  The coupler is ripping the diaphragm off of my Amtrak Dining Car.  Not good.  

My first run C&O, NYC and Wabash cars all had the full-width Diaphragms that hid the fact that the couplers were bending upward.  The couplers were held down by the Plastic Diaphragm floor of the Full Width Diaphragm.

My pictures are blurry because the train was moving in order to put a load on the couplers and get them to show their upward movement.