# AML BETHGONs - Kadee Body Mount Couplers & Squeaking wheel fix



## Ted Doskaris (Oct 7, 2008)

AML BETHGONs - Installing Kadee 906 body mount couplers and fixing squeaking wheels.
Ted Doskaris

These BETHGON II Coal Porter Hopper cars have been out for awhile now, but I finally obtained four of them that had been demonstration show cars. The cars are 1/29 models of the Bethlehem Steel Car Company aluminum prototype cars.

The road names of the cars are Burlington Northern, Conrail, CSX and Norfolk Southern.










The cars include all metal trucks & wheels and a removable realistic looking coal load made of discrete plastic "coal" particles.











Preparing the BETHGON for body mount couplers[/b]With the coal load removed, a car can be placed upside down on its back so the trucks can be removed, and the under frame screws can be snugged down. 
This is important to check when using body mount couplers since the coupler pad ends of the car must be tucked in around the end sills and leveled as best possible.










When using body mount couplers, the factory truck mount couplers (including metal mounting brackets) must be removed from the trucks.











Preparing Kadee 906 Coupler Boxes[/b]
The AML and Kadee 906 coupler boxes look similar, but the AML box is actually thinner in height, and also, has a coupler design unique to AML having an upward offset knuckle, whereas, the Kadee 906 assembly to be used has a centerset knuckle coupler.










The Kadee 906 coupler box needs a shim placed under its rear mounting hole so that the coupler will have the proper distance to the railhead. 
You could raise up the car using a spacer washer over the car bolster pivot posts before the trucks are mounted, but doing this will introduce some amount of wobble to the car.

Shown below is the car coupled to the Kadee 980 track height gauge after having mounted the Kadee 906 coupler assemblies.











With the Kadee 906 coupler assemblies installed, the car best operates on 10 foot diameter curves or greater. There is some drag on 8 foot diameter track curves - tolerable for rail yard access which is what I have.


Fixing Wheel Squeaks & Undesirable Drag[/b]
Under some conditions (typically curve track operation) the AML roller bearing type truck will exhibit some drag accompanied by wheel squeaking sounds due to interference with the brake shoes.
(I first notice this issue on the newer AML PS 4750ft3 covered hopper cars, but since all the BETHGONs has some amount of squeaking, I decided to look into it and fix it.)
There are a number of methods to eliminate this condition, but the most practical method involves temporarily removing the plastic brake shoes in order to file off some material from their backsides.
The trucks do not have to be disassembled for this method.

Perhaps the AML factory would consider changing the brake shoe mold to accomplish the same thing.

(All methods are attempts to mitigate the AML truck's intrinsic design / assembly that lends itself to having a "pigeon toe" side frame stance when looking at the truck head-on.)











AML BETHGON Car Weight[/b]
The example AML hopper car shown below having standard metal wheels and coal load (but equipped with Kadee 906 coupler assemblies) measured 3.43 lbs.











OPERATION ON LAYOUT[/b]
The four BETHGONs were placed at the front of a 63 car train on my under house layout.



















The most stress imposed on the coupled train car is on the 270 degree, 10 foot diameter loop back shown in these pictures.

Shown below is an overhead view of the trailing loco (Aristo BN GP40) coupled to the first car (BN BETHGON) of the 63 car train.










The coupler stress under load is shown below on the inside of the curve.










The coupler stress under load is shown in the next couple of pictures on the outside of the curve.



















Shown below is coupler stress under load for the fourth train car (AML Conrail BETHGON) coupled to an AML PS2 4750ft3 MKT hopper car. (Top view.)










Outside view:



















VIDEO:[/b]

(About 4 minutes, selectable for HD playback in Youtube)
Title: *AML BETHGONs with Kadee 906 Centerset Couplers In 63 Car Train* .



For more info., including a comparison with Aristo's 100 ton hopper and "how to's" detail about truck disassembly / reassembly techniques, see the full article, 
"*AML BETHGONs - Installing Kadee Body Mount Couplers & Squeaking wheel fixes*".


-Ted


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## GaryY (Jan 2, 2008)

As usual a great review...! Thanks for the excellent info and video 

Regards 
Gary


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## Trains (Jan 2, 2008)

Great review, very nice cars. It's to bad I model the 40's and early 50's.

Don


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## NTCGRR (Jan 2, 2008)

Donny, you could change that.

I bought one car from Kidmans at the show just to see what it would take to replace the 1:20th scale coal load. some are over 12" chuncks










whole lot better. I'm tring to add to Teds thread not hijack it.


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## Doug C (Jan 14, 2008)

Greg;

Would you pls shrink the height/thickness of your blue header bar on your website where this article is graciously stored for viewing by the masses ?

On a laptop your site is sample one that due to coding (of some sort) takes up nearly half the screen viewing area leaving not a very satisfying portion to view the good stuff (i hate scrolling down every 3-4 seconds) . . . . . and in this case another terrific ted article. 

Reference: your own, '..bugs take over the screen'.


Thank you for your time.
Doug C 


p.s. just referred a few peoples to this article after acquiring a few units at ST'18.


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## Ted Doskaris (Oct 7, 2008)

Hi Doug,

Greg has vacated this MLS web site since he reach 20,000 posts, and I don't post anything new here having migrated to LSC.

I sent him an email with respect to your comments.

Thank you,
-Ted


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## Doug C (Jan 14, 2008)

Weell LOL

Thank YOU for another useful article ! 

re ceasing use of MLS and dedicating to just one site for posting . . . . considered reposting to LSC where we can post accolades of your past articles then ? 

sincerely, 
Doug C


p.s.
i did receive a invite from Greg to read his signature that indicates contact info but these days i tend to ignore the majority that (go beyond one line), as i consider them a waste of bandwidth, compare similiar to lot of ads in internet (even printed) media. IMHO !


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