Help re: coupler Heights on KATO SD80 and 90MACS is a free Model Railroad Discussion Forum and photo gallery. We cover all scales and sizes of model railroads. Whether you're a master model railroader or just getting started, you'll find something of interest here.


Ignorance is Patriotic
I just finished building 3 Kato SD80MACs and two SD90MACs, and it seems all engines suffer from severely low coupler height, particularly with the rear coupler. Has anyone else run into this and can confirm that it's not just my engines that are off?

After noticing the Kato coupler box was too short and led to some droop, I shaved some Kadee coupler boxes so they fit through the pilots of the locomotives, and screwed them onto the coupler mount. The Kadee box, in which I installed Kadee's #148 "whisker" coupler, did not make much difference; the coupler was still too low.

I then decided to use a .010" styrene shim, mounted on the floor of the coupler box, right below the shank of the Kadee coupler to raise it some. This caused the back of the coupler to elevate and the front to droop even more, actually resulting in reduced coupler height.

Next step, I tried using Kadee's undershank coupler, in which the head of the coupler is elevated from the shank, and this led to the coupler height being too high!

So, it appears as though the the true coupler height lies somewhere between a standard coupler and an undershank coupler, and I'm all out of ideas.

For a quick fix, in my last throes of desperation, I committed the ultimate sin: I used a pliers to bend the shank of the #148 coupler slightly up. This allowed me to achieve the exact standard coupler height I was looking for, although I have some very big regrets about doing this. I know this weakens the coupler and causes it to ride at an angle, but there was nothing else I could do!

After all, this isn't a freight car, where I could just mount some washers on the truck bolster to raise the floor of the car.

Does anyone have any ideas or has already fixed this problem? Do you think I might be able to get by with my "ghetto-ized" #148 couplers?


Diesel Detail Freak
Not sure, I don't own any to have any info. I do however have a P2K GP7 thats having a HARD time keeping its couplers level. They're angled up well enough to cause issues with the tight lock that Sergent couplers have.

We'll see what comes as I assemble more units.


I don't know about your Kato engines. I had a similar problem on a different engine. I used the undershank coupler and, like you, found it was too high. I had enough room to shim the coupler box DOWN to bring the coupler height within specs. Maybe that would work for you?

Hope this helps.

Darrell, quiet...for now

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