MTH Hoppers comming uncoupled while running

Anything magnetic around the layout?

I had a few like this, I just use a small zip tie to hold the couplers closed now.

Nothing that I am aware of. It is far from any transformers, and I do not have any uncoupling track sections setup on the layout.

Tom

If you reverse the car is it the same coupler? Have some Lionel cars with this same problem.

Tom, I have experienced the same problem with R-K cars bought within the last year.  Something causes the coupler to open.  Maybe MTH got a new supplier.  I have not been able to discover a reason.  Never happened until I got these new cars.

RJR,

Yes. Exactly. It only seems to happen with my new rail king cars. I guess maybe call MTH?

Please post what they tell you.

Will do my friend!

I've used "floral wire" on couplers that won't stay closed.

easy to work with and almost impossible to spot. 

I have a Railking passenger car that had the same problem.  I took it back to the shop where I bought it and the owner showed me how to fix it.  There is a pin on the pull down arm that sticks into the knuckle and prevents or allows uncoupling.  He carefully bent the pin ever so slightly towards the wheels and that did the trick

Isn't that pin plastic and therefore VERY fragile?

Could be plastic, could be metal.  Either way,  it has to be bent carefully and ever so slightly.  The other option to fix the coupler (or if the pin does break) is to replace the pull down arm.

Tom,

What's the item number of that WM 2-bay set you have? This is will help in identifying its production date. Additionally, what other item numbers are you having issues with as you've noted, "It only seems to happen with my new rail king cars."?

Thanks,

MTH

out of the 7 or 8 premier freight cars i've purchased over the past year , there were 4 that have uncoupling issues. i had to take a screwdriver to push outward on the coupler shank( really hard to explain here). you want to be careful when you apply pressure against the carbody doing this. so far i've been able to get 3  cars fixed so they stay coupled up as intended.

on this past years production,some thing changed the way the trucks were made. i dont know if the railking cars ' trucks use that flat plate on the bottom. im a 100% premier guy.

While on one car I used glue to "weld" the coupler closed, I should not have to give up uncoupling ability.  Now that, as evidenced by the above question, MTH is alerted to this new issue, I expect it will be corrected.