Lionel coupler help. Fixed

I spent a few hours fooling around with style coupler.  I cannot say anything got better.

On one car, the long end of pin (opposite the coupler) was slightly bent so the shaft do not exert enough force to keep the coupler closed.  Straightening the shaft was my only success- that coupler works.  What I did find is a fine balance between the weight of the uncoupling plate and the spring to keep the coupler closed.  As the train moves it is bouncing, pushing and pulling on the coupler.  When bouncing and pushing coincide the coupler opens.  After being annoyed by this I removed the uncoupling plate altogether.  That coupler works perfectly and you can still uncouple by pushing the tab.

By the way, I have a number of cars with this truck/coupler combination that work fine.  Trying to compare a good one to a problem one is difficult since the way this truck is assembled, disassembly is destructive.

Good luck.  Happy 4th.

This is the same style that Menard's uses on their cars.  There is a root cause of many coupler false openings, it's the internal lever that is part of the magnetic actuator.  The coupler is fixed to the truck body, but the releasing mechanism is held in place by a sloppy fit around the axles, and it moves around some during operation.  If the lever is bent too close to the actuating arm of the coupler, the movement can open the couplers.

Here's a link to my Menard's Coupler Fix, I suspect these have exactly the same problem.

Thanks Dan and John. 

Thanks, John.  I wasn’t aware that Menards used the same coupler style.

Using the suggestions above I figured there is a fix. I disassembled the knuckle and filed the pin contacts as we do on other couplers. Per the above recommendations I noticed a flat pin that engages the knuckle was scraping the coupling housing. I bent it so as to stay centered allowing for more engagement. Operates as it should now. I should have taken pictures cause I know this explanation isn’t that helpful.