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Bachmann
Coupler Mod - A variation on TOC's simple
method to improve Bachmann coupler reliability.
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Over in a myLargescale.com Forum thread, TOC mentioned how he fixes Bachmann couplers with a simple modification. I tried a variation of his idea and it greatly improves the reliability of the Bachmann Couplers on my road. My modified cars can now be run at the head end of long (15-20 car) trains with no uncoupling experienced. I was so happy with the results that I decided to document it here with photos and share TOC's ideas along with my variation in a format that is simple to understand and apply.
TOC's method is to replace the plastic pin at the pivot point with a 1/2" #4 pan-head sheet metal screw and flat washer driven up from the bottom through a #50 hole drilled in the truck tang... quote: Originally posted by Curmudgeon
Occasionally I get a Bachmann that has a problem.
Rather
than use the sheet metal screw, I
decided to use a 3/8" 6-32 machine screw, nut and flat washer, with
the screw head hidden in the coupler pocket. Both methods require some
minor trimming of the coupler pocket, which I will detail below. The
result of either fastener is to reduce the slop and droop in the coupler
head at the pivot point, thus reducing uncoupling due to load stress.
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| Side and
Bottom View of Truck Mounted Bachmann Coupler. Note the plastic pin at the pivot point. |
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| First,
Remove the coupler from the truck and locate the underside of the
plastic pin at the pivot point. |
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Squeeze
the slot in the pin with pliers from the underside and push through the
coupler shank to remove. |
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| Remove the
plastic pin and the coupler head. Note the half collar on the coupler
pocket. |
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| Trim off the
half collar and any excess on the coupler pocket so that the
collar is flush with the coupler shank as shown at left. |
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| Ready the parts for assembly: 1 ea. 6-32 x 3/8 inch Machine Screw, Nut and Flat Washer. I use Locktite brand Threadlocker to hold the nut in place. |  |
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Push a
6-32 x 3/8" machine screw down through the collar hole from the top
of the coupler pocket until the threads are exposed as shown at right. |
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| Place the coupler shank back over the coupler pocket collar. Be sure the coupler head is oriented as shown. The fat end of the lift pin should be up when the threads of the screw are visible. |  |
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| Install the
Flat Washer. Coat the threads lightly with Threadlocker then install the
Nut. To be
sure the screw head is seated in the coupler pocket, screw the nut on
tight, then back off checking the head pivot until there is only slight resistance.
When properly adjusted the coupler head pivots with very light resistance. |
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| Add a drop
of Threadlocker on top to help hold the Nut in place and replace the
coupler assembly on the truck.
This completes the modification for Freight Cars. |
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| Installing the modification in Passenger Car trucks requires an extra step. Note the Collar on the end of the Coupler Tang in the left picture. This collar must be removed by trimming the Coupler Tang on the truck as shown on the right. |  |
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| When the
Coupler Tang is properly trimmed, the mod works equally as well on
Passenger Cars. |
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| I want to add a
special Thank You to Dave Goodson (aka The Old Curmudgeon -or- TOC) for
developing the original idea for the modification and his quick response
to my email questions. Once this mod is installed on your Bachmann Couplers you should experience no uncoupling problems due to coupler droop. |
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