Yep, those two should mate just fine.

 

It sounds like you're using different car lengths to make up the train, so if you have a 60' car fitted with a truck-mounted coupler, it has more lateral movement on a curve than a 40' body-mounted coupler, you should be able to mix the two but make sure the car lengths are the same.

 

Thanks both of you.
I am actually using the same length cars. What I have discovered is the the couplers on the cars with isolated ones are too short, so the cars are touching each other on curves. I’ll try replacing them with longer ones.
Cheers, Alastair.

 

Ah! In the UK with OO scale we call that Buffer lock, but as US cars don't have buffers.....?

I can't remember what number Kadee it is, but they have a coupler that fits on the car body that allows the whole coupler to swing in a similar way to a truck mounted coupler, they should work for you, or as you say, a longer coupler may also work.

 

Yes, the knuckles will coupler together fine, but actually, you are trying to run 2 different different kinds of cars with 2 different methods of coupler mounts….it will be beneficial to run cars together that have the same types of coupler mounts….ie: truck mounted coupler to truck mounted coupler, and body mounted to body mounted coupler….

 

It seems you are running cars on too tight of a radius curve. The cars should not be rubbing/touching regardless of how couplers are mounted to the cars.
While 15 inch radius exists; 18 inch radius is traditionally the bare minimum. However that limits you to short car lengths only. I speak for many I'm sure when I say 24 inch radius should be considered the minimum.

Passenger cars tend to disagree with anything smaller than 24, with a couple rumored exceptions.

 

In the pics above, BOTH pics show truck-mounted couplers on passenger cars.

The OP didn't tell us what his minimum radius is.

If those two cars are derailing on curves when coupled together, it looks to me like the coupler assembly in the upper pic is being pulled "to the edge of its travel" when in a curve. Then (of course) it can "go no more" (even though the lower coupler is unrestrained and wants to keep swinging) and it reaches a point where the upper coupler won't "give no more". And then... derails.

The "restraining" assembly (in the top pic) looks to be glued on and not easily removable.

Again, OP, what radius curves are you using?
As you've found out, they may be too tight for passenger cars.

Also be aware that truck-mounted couplers are notorious for derailing when backing up (even on wider-radius curves)...

 

.assembly in the upper pic is being pulled "to the edge of its travel" when in a curve. Then (of course) it can "go no more" (even though the lower coupler is unrestrained and wants to keep swinging) and it reaches a point where the upper coupler won't "give no more". And then... derails.

You are right. I checked it out and the trucks on the Rabido and Walthers cars don’t turn far enough.

The trucks on the (less expensive) Bachmann ones turn much further.

I guess I’ll stick with the Bachmann ones.
Cheers! Alastair.

 

I’m running 85’ Budd coaches on 22” radius EZTrack. They are supposed to handle that. My Bachmann ones do fine. The Rapido and Walther ones have short couplers. I now think that’s the problem. I’ll replace them with longer couplers to see if that works.
Cheers.
Alastair.