MTH SD-70 and Kadee Coupler Problem

Good Day Chuck, 

 

Try this....get a dremel drill or metal saw and cut off about 1/16" off the back of the metal Kadee coupler pockets. That should work. That is how I modified the Kadee 805's.

 

Regards,

Swafford

 

Chuck,

Found some old photos of the Premier scale-wheeled SD70M-2. The photos show the material I removed from the boss on the trucks.

Thanks,

Naveen Rajan

 

Here are some of my old pictures with the back of the 805 coupler pocket cut off.

 

Regards,

Swafford

Once I have my Kadees assembled in the draft gear box, I take them over to the bench grinder and grind down the back of the box all the way to the coupler shank and then form some nice round edges. It does not matter if the coupler shank is exposed.

 

 

 

This is a Dash 8 dummy unit that I converted to fixed pilots and added the Kadee couplers. Just about all engines need the coupler box modification to allow the trucks to swing properly. Unless of course, if you have the engine completely apart, you can cut that tab off of the trucks, and I have done that too. The coupler box on the bench grinder is much quicker and easier though.

 For other guys who see this:

You can use the short gear boxed KDs without any cutting. They work a bit different in that the slack action is the opposite of the normal. (#743 for example)

 For that reason, I cut the longer boxed version like posted above. ( I think Frank taught me!).

 The only difference for me is I use the newer #745 that have plastic boxes with metal couplers. Makes cutting very quick. Helps to make sure there's no ground problem with wheelsets.

Two ways:

 

1. Use the Kadee 806 or 743.
2. Hold the 805, 740 or 745 coupler box with a pair of pliers and shave 1/8" off the rear of the box with a Dremel.

I found that the short couplers/boxes don't have the same amount of swing as the standard 805 or 740 couplers. The shank is a little different and I needed maximum travel, especially when MUing engines, so I swapped out all my shorties to standard length couplers and ground down the boxes. Being a 3 railer, I always use the metal boxes for strength and durability.

Followed all your advice and shaved off some excess coupler box.

 

Works great lasts a long time.

 

Thanks!

 

Chuck

I hadn’t thought about grinding (instead of filing) & removing the entire back wall from the Kadee coupler box. Thanks for that advice. I look forward to trying this approach on my next MTH scale-wheel locomotive.

Thanks,

Naveen Rajan

Good morning

 

I also have altered either the coupler box or the truck block, All SD40-2. Check the locomotive on its wheels on a flat surface some locomotives don't have to be altered at all. When the locomotive is upside down on the bench the truck is not sitting parallel with the frame.

 

Clem k