Converting Old N Kato SD40 Rapido to Kato Knuckle Coupler

[busdriver]

Hello,
I'm converting my RR to knuckle couplers having given up on transition cars to the Rapido type.  Most of my equipment was purchased back in the 80s and 90s and are getting new trucks/couplers.  With new equipment now hitting the main line, I have some engines that need updating.

I have several Kato SD40s with the body mount Rapido coupler with the copper spring plate behind it.  The Kato short shank couple goes nicely in the space, and is at the perfect height.  However, there is a gap at the top of the coupler pocket that the coupler will wiggle up the pin while running on the layout resulting in an eventual height difference that uncouples the train. 

What can I put on top of the coupler on that pin to keep it from being able to ride up over time?

I'm not a modeler, I'm more of an operator, so I don't have all of the usual supplies of parts and pieces to make something out of.  However, I'm willing to purchase whatever.  Ideally, a very tiny bushing or washer is what is in my mind. 

Thanks in advance for any tips, ideas, or tricks.

I tried to add a picture, but it says I'm not allowed to do that.

Bryce

[dandopinski]

I used styrene strips from Evergreen, either .020x.125 or .020x.156 mounted underneath the coupler box.

[trainforfun]

My first KATO locos were all with RAPIDO couplers , I converted them using MT ( Micro Trains ) couplers , you can still use the clips without using the brass part .
Sometimes I used the plastic clips but most of the time I used a screw that come with the couplers in the same hole where the clip goes in .
A lot better to use the screw , sometimes the clip come loose and fell .
To get the right number for the MT coupler go to their site and there is a list of all locomotives by all makers and models ( or almost )

[busdriver]

Thanks for these tips.  I have ordered some styrene to play with.  Regarding the microtrains couplers, I have seen one that supposedly slips right in, but I have packs of 10 Kato couplers that I got for $6 per pack.  I would love to get those to work since I have 8 or 9 of those SD40s.  Save some $.  However, if I can't get Kato couplers to work, I will definitely go the MTL route.  I like their stuff.

Bryce

PS:  Does anyone know why I can't post a picture?  Am I too new to the group?

[peteski]

PS:  Does anyone know why I can't post a picture?  Am I too new to the group?

Yes Bryce. See https://www.therailwire.net/forum/index.php?topic=43673.0

[busdriver]

Ah, thanks.  I need to find some more things to talk about

Bryce

[OldEastRR]

Doesn't MTL make conversion kits to change engines from Rapido to MTL couplers? The molded pieces fit into the big truck coupler gap  and have brake hose detail molded con.

[peteski]

Doesn't MTL make conversion kits to change engines from Rapido to MTL couplers? The molded pieces fit into the big truck coupler gap  and have brake hose detail molded con.

Yes, MTL made pilot conversions for the early Katos which had open pilot and truck-mounted rapido couplers.

But Bryce stated "I have several Kato SD40s with the body mount Rapido coupler with the copper spring plate behind it. " so he just needs to get an MTL coupler (not the complete pilot).

[Tom4884]

I have a bunch of Kato sd40 and SD45 locomotives that I converted to Micro-Trains couplers using the 1015 couplers (not sure what the new numbers are but the MT site does post the old numbers with the new).  I just pop the brass piece out and slip the couplers in, replace the clip and done.  You can do this with the shell still on the frame, but it's much easier if you take the shell off then do the couplers.

Tom

[busdriver]

Thanks for all of the additional info.  I have some styrene coming to see if I can use my existing Kato couplers.  I also found some tiny black washers that came with some MTL trucks I ordered that may help as well. 

Bryce