1:20.3 scale AMS/Accucraft Passenger Car Coupler Modification for negotiating  48" radius curves


I replaced the original coupler with an AMS/Accucraft coupler AP11-737. It has a longer shank than the coupler that came on the car.
I have a number of AMS/Accucraft Passenger cars that I have wanted to run on my  1:20.3 indoor layout that I am building.  These cars typically are used on layouts with a 6ft radius or larger curves.  How ever I am limited on the space in which I can build the layout and relegated to between 48" and 54" curves which is fine for my Bachmann Spectrum outside frame 2-8-0's and C-19 as well as all my other rolling stock.   One area of my layout there is a curve that is 48" radius and when a passenger car goes around this curve, the couplers bind and cause the car to derail due to the short length of the body mounted couplers.

This is my solution to the problem​​ which was an easy fix and took only a couple of minutes to do.
I removed the original coupler and then made (2) 1/8" thick shims that were placed in the recessed area for the original coupler.  This lowered the new Accucraft coupler to be at the correct height to mate with the couplers of the other rolling stock.

I then placed the new coupler in place. Inserted the original screw  through a washer and 3/16" long brass eyelet.  Inserted the screw into the hole in the shank of the new coupler and started the screw.  Before I tightened it all the way down I inserted one of the original springs into the shank slot. then screwed the screw all the way down.
Trouble spot.  this crossover.  Outside curve is 54" radius,  Inside curve is 48" radius
Issue Resolved with new longer coupler.