0-27 passenger cars won't stay coupled

[Roadmaster]

Hi All,

I have a set of postwar 0-27 gray top passenger cars - 2421,22 & 23.  The cars were purchased piecemeal at auction or on-line.  

No matter what I do, they won't run through a switch or UCS without one of them uncoupling.  I am using Gargraves phantom rail flex track & switches (4 Gargraves & 3 homebuilt).   I use Lionel 6019 UCS.  I have tweaked the trucks & couplers and the switches for shorting & clearances.  What do I need to do to stop the cars uncoupling?  They are uncoupling, not popping open.  If I reverse the car, the same coupler opens in a switch.

Roadmaster  (Ha)

[TrainLarry]

Does this happen on all the cars, or just one? Since the problem follows the coupler, then it is that coupler at fault. Are the couplers at the same height and parallell to the rail? If not, the couplers may separate vertically without the knuckle opening. Check the tension of the lock spring, as a weak spring can cause the coupler to open. Make sure the armature plate snaps all the way up when pulled down; if it hangs down, it may get caught on a switch or uncoupling track.

Larry

[phillyreading]

Do these cars have the little pre-war pick shoe for uncoupling? It's quite a common thing with Gargraves switches and post war Lionel cars. Try to use either Ross Custom switches or go to Lionel's postwar 022 switches. You may not want to but the last resort is to replace the older trucks with something more modern, like from the mid 1960's. I looked these up in Greenberg's price guide and the years for these cars are 1950 to 53.

[servoguy]

If you have couplers that are actuated by sliding shoes, it is likely that the shoe is contacting the center rail as the car goes through the switch.  This can be a problem with 022 switches, and the solution for these switches is to bend the end of the fat center rail down slightly.  Run one of the cars through the switch by hand and see if you can determine where the shoe is contacting the center rail.  You may have to grind a little off of the center rail.

[Roadmaster]

TrainLarry, PhillyReading & Servoguy,  Thanks for the answers.  All the cars (& the locos) have sliding shoe contacts on the couplers.  I have shimmed or bent the trucks & couplers so that they are all aligned &  squarely fixed to the car frame.  the couplers are uncoupling not popping open or lifting over one another.  I have bent switch rails, glued in 'ramps' at rail ends and isolated rails that were contacting the shoes.  

The 3 home-made switches were built to Ross full scale drawings & have fewer problems with uncoupling, but I used hot glue to anchor the rails in slots in the ties, so they need constant maintenance.   The best advice is to get Ross Custom switches.  Even on eBay, they are expensive.   I have 022 switches, but I would rather not use them.  Same for changing the trucks.  I'll just bite the bullet & get some Ross switch

Roadmaster