[GUIDE] Coupler Change on N Kato SD45 & C30-7 (& Probably Others)

[TrinityJayOne]

When I reviewed these locos I pointed out that the coupler shanks are waaaaaaay too long and the cause of much discussion online. Let's have a looksie!

Notice how massive that shank is compared to the one on the SD24, even considering the larger pilot. Now look at the gap between the SD45 and C30-7. Those trains are actually coupled!

I found a lot of different (often contrasting) opinions regarding how to fix this problem, so I figured I'd give it a crack myself and make a guide of it. These steps worked on both my SD45 & C30-7 locos, and will most likely work on any other recent N Kato diesels that have the same problem.

YOU WILL NEED

• A small file/s, preferably with a square or rectangle profile
• Some Micro-Trains 1015-1 couplers (two per train)
• A small flathead screwdriver
• Steady hands

METHOD

1. Remove the shell and set the mechanism aside.
2. Hold the stock coupler to one side so that the copper/brass spring at the back of the coupler assembly sticks out, then pry it out with your screwdriver (be gentle, it WILL go flying).
3. The black clip that holds the coupler in place has two hooks that latch onto the shell. Gently wedge your screwdriver between the clip and the side of the shell and it should pop right up. The other side should now come free just by wiggling the clip around a bit.
4. If it hasn't already fallen out, remove the coupler itself. You should now have three pieces as pictured below- the coupler, the spring and the clip.
   
   
   
   
   
   
5. The hole in the pilot is not completely square, there are two small bits sticking out in the bottom corners that need to be filed away (neglected to get a picture of this, sorry!). File from the SIDE, not the TOP, as the MT coupler box is already flush with the hole on the top & bottom sides and you want to keep it this way.
6. Stick one corner of the MT coupler box in the hole, trip pin pointing away from the shell, then try to straighten it up while applying light pressure. If you were gentle with the above filing it won't fit yet, but if it does just skip to step 10.
7. Very gently file one side of the hole. Just a few short strokes with very little pressure will do, and try to keep your file as level as possible. Repeat on the other side of the hole, being very careful to file both sides evenly (you don't want an off-centre coupler).
8. Blow the filings from the hole and then try to fit the MT coupler box in again. Give it a couple of tries before doing more filing as you want the fit to be as snug as possible.
9. Repeat steps 6 & 7 until the MT coupler box fits.
10. If you were gentle enough with the filing the MT coupler box will stay in place by itself. You could use glue to secure it but I wouldn't recommend this, as the risk of ruining the MT coupler is too great. Instead just use the provided screw and the hole in the shell that the original clip used.
11. Push the screw through the hole in the MT coupler box, then position it so that the head of the screw is only just going to clear the shell. This should align it with the hole that original clip used.
12. Slowly turn the screw while applying a little pressure until it bites into the hole. You may need to press down on the rear edge of the MT coupler box so that it doesn't move up the screw as you do this.
13. The screw will get harder to turn as it goes in. DO NOT SCREW IT ALL THE WAY, YOU MIGHT GO THROUGH THE SHELL! Only screw it in enough for the head of the screw to be flush with the bottom of the pilot, as below. Because the MT coupler box fit was already tight this is more than enough to hold it in place.
    
    
    
    
    
    
14. Replace the shell and try it out! You should find the coupler height to be spot on and the new shank length far more agreeable.
    
    
    
    
    
    

Please provide feedback if something isn't clear or doesn't make sense!