Lionel 627 Coupler Failure

[Anonymous]

Good morning and happy New Year to all.

 

I am dealing with an issue of which I had heard, but not previously experienced: Coupler failure. I purchased a neat Lionel 627 (the PW Lehigh Valley 44-tonner) at a recent train show. I cleaned and lubricated the motor and the old engine runs fine by itself. However, when the one coupler has cars attached, the engine inevitably breaks away via its own couple and sails merrily down the track by itself, thus causing alarm and consternation to the hard-working railwaymen of Middletown.

 

The difficulty appears to be a plate with a pin under the coupler, which will not stay flush and then allows the coupler to spring open. Is there anyone on here who has experienced this kind of problem and knows a fix? Thank you very much for your help.

[Buckeye Riveter]

I had a MTH coupler do this to me.  It had been molded completely wrong and would not work no matter what I did.  I ended up replacing it.

My first course of action would be to use a small flat blade screw driver and "clean" any excess molding from around the recess provided for the pin.  Dirt or molding "scrapes" may be the culprit. 

 

[USNRol]

just fixed this same problem on a operating milk car I had.  Like you described the tension on the knuckle during operation combined with minor normal "working" while rolling down the track was causing my pin to work out the bottom and the knuckle would open.  I fixed mine by putting some scrap blocking (two small plastic pieces; could use anything) under each end of the spring-steel spring that maintains the pin in the up position...apparently my spring wasn't quite strong enough.  But with the blocks under each end of the spring it effectively shortened the spring and makes it harder to uncouple but still easy enough for the remote track to uncouple.  Problem solved. 

 good luck

USNRol

[lionelsoni]

It is possible that the centering spring, the coil spring under the armature (which is the "plate" that you mentioned) is weak.  But, even with a good spring, the armature sometimes droops a little.  I often find that I can get the armature to push the pin up farther by putting a very slight upward bend in the armature near the end closest to the spring.

[Anonymous]

Thanks for all these good ideas and suggestions, folks! And I have learned something new. I did not know what the "armature" was, though I had seen the term on many occasions.