Hi everyone. I have taken my first step into 3 rail scale with the purchase of a new MTH 4-6-2 Ps-4 Southern Crescent Limited set. 
The set comes with four 70' pullman cars and I also picked up the two add on cars. Overall, it's a nice set, except for the bent bell bracket. I'll be on the phone with MTH on that this morning.
Anyway... try as I might, I couldn't keep the cars from derailing and decoupling. Grrrr.
So after a frosty beverage, I decided to have a closer look at the issue. The most obvious problem I found was that the trucks were WAY too tight, and in many cases striking the coach steps. So all my cars, fresh from the factory were disassembled and got their trucks properly adjusted last night. They really need to stop employing gorillas. 
I also found that the coaches bases were misaligned to the body by a few mm, causing truck to coach step interference in curves. The good news is now all the cars roll smoothly on my 048 and 054 curves, although I should send MTH a bill for my time. (Sarcasm: Great job inspector #4!)
What I have not been able to solve is the decoupling issue. They will run fine for a few laps and then or two of the cars uncouples. ??? Why in the world would it do that?
These are the couplers that push back to release. I thought it was me at first, but no, they are locked up before running. Any ideas how to fix this issue? Maybe 6 pullman coaches is too much for it? I have never had any problems with my Lionel couplers, but those were plastic ones on Berk Jrs.
Thanks for any advice...
