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Diesel Detail Freak
Well, as most of you may know I'm in the slow process of switching to Sergent Eng. EC87 couplers. Yesterday I installed some on one of my Walthers Airslides (have 6). My god was it annoying!! The bevel headed screw, and notched coupler box cover interfere with the movement of the coupler! If I loosen the screw, the cover swivels too, if I tighen it, it causes the plastic ring on the inside to expand and freeze the coupler up. I carefully burred the coupler hole open... then tightened it again, and the COVER freezes it up now! I might have to get a new cover, and screw for EVERY Walthers car with the beveled screws! I think I may add a washer too.


Diesel Detail Freak
E-mail reply from Frank.
Hi Josh,

This is pretty common. We wanted the shank on the EC87 to be prototypically thick, but we also wanted it to fit into a KD#5 box. However, since the inside height of the KD box is actually less than needed to accomodate a coupler with a scale thickness shank, we had to make a tradeoff. The tradeoff was to design the shank on the EC87 to be as thick as possible and still fit into a KD#5 box.

Some manufactures of rolling stock that provide cast-in coupler pockets apparantly noticed that the shank on the #5 coupler has a lot of vertical slop when mounted in its box, so they sought to rectify that problem by making the inside height of their cast-in coupler boxes even smaller. This reduces to vertical slop of the #5 coupler when mounted in their box which is a good thing if you are happy using KD #5 couplers. A problem arises when you try to fit a coupler with a more prototypical shank height in the box -- it won't fit!

There are two ways to solve this problem. One way is to replace the cast-in coupler pocket with a KD#5 pocket -- that's probably not very practical on an Airslide without major surgery. The other way to solve the problem is to thin the shank on the EC87 so it will fit within the given height. Since, not a lot of metal has to be removed, you can simply use a file to remove metal on the bottom of the EC87 shank. If you have one of our assembly fixtures (part number AFC), this is easy. You hold the fixture in a vice, load the coupler in the fixture, and quickly file the shank down. Its a little more difficult if you have to hold the coupler in your hand while filing, but its still very doable.

Frank Sergent

> From: " Admin" <E-MAIL...>
> To: E-MAIL...
> Subject: Coupler question
> Date: Sun, 09 Apr 2006 21:11:27 -0700
> Hi, I've ordered several of your couplers, but i have an odd question, I have two Walthers Airslides, and the coupler boxes create to much friction on the coupler, is there a suggested oil, or a way to make the coupler bar thinner so it can move? It might need a tad on the hole but the box is the biggest issue.
> Josh​


Coal Shoveler
The Kadee box is also sloppy if you don't use the separate spring. Many models now use the McBotchmates, which are whisker springs. Without that separate spring, the boxes are shallower. So, when I replace the McBotchmates, I have to file down the cover thickness, so the Kadee spring doesn't get crushed.

Sounds like the Sergeant couplers are even thicker than the Kadee/separate spring combo....



Diesel Detail Freak
The Sergent couplers are fairly thick on the drawbar side, and use a sring to cause resistance instead of centering. This does mean you have to manualy "center" it to couple, but thats not bad, as one coupler has to be open anyways. They're much easier on a curve when coupleing because the couplers will stay in the postition you left them in.

The issue will be solved (for me at least) by filing a little bit of metal away, and changing the coupler box screws to a flat head, with a tiny washer, instead of the tapered head Walthers includes.

I'll take compairson and installation pictures as soon as I have a new camera.


Heh, you think putting a Sergent in a Walthers airslide is bad? Fixing the coupler issue on my Airslide was a cakewalk compared to fixing the coupler issue on my Kadee boxcar. Now that's one funny draft gear box! Took half an hour to figure out how the dang box comes off (and that was after breaking one of the covers in half). The inside wasn't any more conducive to installing a Sergent. The kingpin was all angle-y and fat. But I did get it all figured out.

And if you're still wondering, yes, I did liberate the Kadee couplers from a Kadee boxcar. So sue me.

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