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Athearn Blue box GP38-2 / Kadee #37 Coupler - centre-height is at least 1.0mm too high.

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  • Member since
    March 2012
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Posted by trwroute on Tuesday, March 16, 2021 4:10 PM

maxman

 

 
trwroute
On this particular frame, the coupler mounts on TOP of the pad.

 

Never understood how this was supposed to work.

Looks like you have to remove the shell to install the coupler.  If you permanently install a plow it becomes impossible.

 

The shell does need to come off to mount the coupler.  I have body mounted the front coupler if a snow plow is installed.  Also, you will probably remove the trip pin when a plow is used, then you can easily remove the shell by just sliding the coupler out while still attached to the frame.

Chuck - Modeling in HO scale and anything narrow gauge

  • Member since
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Posted by maxman on Tuesday, March 16, 2021 3:58 PM

trwroute
On this particular frame, the coupler mounts on TOP of the pad.

Never understood how this was supposed to work.

Looks like you have to remove the shell to install the coupler.  If you permanently install a plow it becomes impossible.

  • Member since
    November 2012
  • From: Kokomo, Indiana
  • 1,463 posts
Posted by emdmike on Tuesday, March 16, 2021 1:47 PM

Back in the day when these where the best engines and only more modern EMD's on the market(other than the Roco/Atlas or brass), we would grind down the mounting pad with a milling bit in the dremel motor tool. Then drill and tap the hole to 2-56.  After slightly shortening a Kaydee #5 box, you would test mount the coupler and check it with the Kaydee coupler height gauge.  This also helps set the trip pin height if your keeping that feature for its remote uncoupling abilities.  Back then, Kaydee was all we had, #5 was the go to coupler, no wisker spring options back when these engines were first on the market.  Doing the couplers was part of the process of also hard wiring the trucks to the motor, tuning the trucks to run quieter, and redoing the headlight to light up the lenses instead of the whole darn cab.  Even a preteen with a summer job cutting grass could afford these when they were new.  Cant do that as easilly now.   As also mentioned, you can cut off the pads and build up new ones that are attached to the body itself.   I never messed with lowering the truck bolster height, If it want that much of a difference, I will buy brass or a more recent model.    Mike

Silly NT's, I have Asperger's Syndrome

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Posted by SROC99 on Monday, March 1, 2021 11:35 AM

First you must understand that our coupler conversions are base on the single model we have on hand and we found that many Athearn locomotives and rolling stock had many coupler height differences even in the same production run. So we list a coupler recommendation on the actual model we have which could differ from the same model you have.

Updating our older conversions is not a very high priority right now.

A #37 is a medium underset coupler that raises the coupler head, a #32 is an overset coupler that lowers the coupler, and the #38 is the centerset.  

Each offset coupler is .050" higher or lower than a centerset coupler, the thickness of the coupler shank.

As previously mentioned you can relpace any 30 series coupler with a combination of a #252 draft gear box and a whisker coupler. NOTE that the last digit in each series are the same configuration. So a #37 is the same as a #147, #38 the same as a #148 and so on.

I do think we'll make a standard package of #252 boxes and whisker couplers.

Sam Clarke, R&D Kadee Quality Products.

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    March 2012
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Posted by trwroute on Sunday, February 28, 2021 10:05 AM

Here is a pic of a Athearn GP40-2 frame showing the pad...

As far as correcting the Athearn truck height, here are a couple of photos of a how-to that I posted on the old Atlas board around 11 years ago...

Chuck - Modeling in HO scale and anything narrow gauge

  • Member since
    March 2012
  • 716 posts
Posted by trwroute on Sunday, February 28, 2021 9:44 AM

On this particular frame, the coupler mounts on TOP of the pad.  This makes all the normal solutions backwards.

Kind of weird!

Chuck - Modeling in HO scale and anything narrow gauge

  • Member since
    March 2012
  • 716 posts
Posted by trwroute on Sunday, February 28, 2021 9:14 AM

I ran into the same thing when converting Athearn BB GP38-2, GP40-2, and GP50.  It's the design of the frame.  The problem is, the truck bolster is too high.  There have been several articles written about lowering the Athearn truck height, but I usually filed the coupler mounting pad, drilled a hole, used a 2-56 tap and screw, and screwed the coupler box to the thinned pad.

Or, you could cut the frame pads off and body mount the coupler.

Chuck - Modeling in HO scale and anything narrow gauge

  • Member since
    April 2016
  • 252 posts
Posted by Lazers on Saturday, February 27, 2021 12:17 PM

 and thank you for your replies. The reason I fitted #37's is because they are what the Kadee website & download states to use. The instructions and diagram are quite precise and the T-shape (as shown) is an exact match for the Chassis die-cast on my model.

Possibly, the Kadee info is incorrect or intended for a slightly different version? If push comes to shove, I will file the chassis down or try a different combination.

However, as stated this was my first venture and having got a bit of experience and looked at all the different diagrams that were enclosed with the instructions, I am confident that I can make an informed choice, for my next purchase.

I.e. I will obtain a multi-pack of #148's. I have followed threads about KD's for sometime now. The Whisker design seems much more suitable.

Thanks again, regards Paul

"It's the South Shore Line, Jim - but not as we know it".

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Posted by charlie9 on Saturday, February 27, 2021 9:37 AM

In the past I have reduced the thickness of the coupler shank by filing the appropriate amount of material off the bottom of the coupler and then installing it with a shim on top of the same thickness as the amount of material removed.

If your coupler is too low, remove the material from the top of the shank and place the shim underneath.

Grizlump (grouch German)

  • Member since
    April 2016
  • 252 posts
Athearn Blue box GP38-2 / Kadee #37 Coupler - centre-height is at least 1.0mm too high.
Posted by Lazers on Saturday, February 27, 2021 8:26 AM

 

"It's the South Shore Line, Jim - but not as we know it".

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