I installed a Digitrax DN163K1B decoder in my Athearn SD70M and it clearly does not fit as you can see from this photo. The decoder jammed into the shell preventing the shell from seating all the way down. I ran it for a 1/2 hour before noticing that the coupler was really high above the track. When I pulled the shell off the decoder remained in the shell. Anyway I’ve spent the past 4 hours searching for a solution and there are too many who say that this is a drop-in and I’m here to say that it is not. I read the bulletin from Athearn which recognizes a problem with some of their models but mine (17415) is not in the list and it is not the older one that had to have the motor removed to solder on wires. Digitrax only refers this problem back to Athearn. So has anybody had my problem and how did you solve it?
the dn163 k1b is the correct decoder. i have just installed onein an athearns sd 70m fits like a charm no problems.the only problem i see is that the front and back fit into groves like a kato,which should prevent it from comming off in the shell
Well mine must have shrunk because the decoder will not fit all the way into the shell. It works great without the shell or if I don’t want to pull any cars. The only way this is going to fit is by cutting off the decoder motor tabs and soldering on wires or maybe grinding out the inside of the shell.
http://www.athearn.com/ProdInfo/Files/ATH_N_DCC_Instructions.pdf check this out.if this don't help,try a google search for a decoder install for athearns sd70 m.
Try putting it together again, making sure the decoder is under the front and rear notches in the frame and pushed all the way forward in the notches(I suspect you already did this part, but I wanted to cover all of the bases). BEFORE putting the shell back on, remove the fuel tank(the fuel tank is in two pieces and each piece pulls out away from the frame instead of pulling down on the tank). Put the shell on, hopefully able to make sure it is seated all the way down, and then replace the fuel tank. On mine, the shell initially would not go all the way down, and it appeared the decoder was preventing it, but it turned out to be the feul tank. The feul tank would, however, go all the way back on after replacing the shell.
Yes I saw that but my model number is not on there. Mine is a newer one. Ok, I measured the decoder which is 0.420” wide and the inside measurement is 0.409. That’s 0.011 too tight with taking in account for clearance. Also, the distance between the Light lenses is 8.5” which is exactly the same as the Decoder LEDs and that leaves 0 clearance for the LEDs. It just isn’t going to fit at all. The DN163K1C has the smaller LEDs which will help with the LED clearance, but I don’t know about the width problem.
this is probably your problem after trying to put my shell back on i had to get a small screw driver,and push in right behind the fuel tank.after working it a few min it pop into place
This is another problem because the decoder is so long that only the front slot is connected and it will not fit under the rear slot. No because the shell comes no were near the fuel tanks. I did look at that yesterday when I notice the couplers were so high that they went right over my car couplers with out touching.
I had this same problem with the Digitrax decoder. I gave up and switched to the comparable TCS decoder. Problem solved. Jim
Ok I finally got the fuel tanks off. I’m glad you told me to separate them. They were glued on so I’ll have glue them back on. Here is a photo of everything disassembled
The Motor contact tabs on the Digitrax decoder don't fit inside the shell. You can use the decoder installation guide on TCS website for tips, even on the digitrax decoder as they are similar. Basically you need to remove the tabs and solder a peice of decoder wire from the motor leads to the decoder. There was an articale in N Scale Railroading a few years ago about installing a decoder in these too. Sorry don't remember which issue.
Changing decoders did the trick! Thanks Ok just on a hunch because so many have said it should work, I opened up another DN163K1B package that I had for another Loco on order and installed it. It fit like a charm and the shell went all the way down. I put it on the track and even connected up some tanker cars. It’s running great right now. I guess whatever machine made this first decoder must have been worn out or maybe out of adjustment, because this new one fit all the way into the groves and the LEDs tuck in nicely inside frame. I don’t know what to do with this other decoder. I guess I’ll have to by another Kato for it, because I don’t know how to explain it to Digitrax.
Johnny... I would send it back to Digitrax...and give em the url for your post here on TB...tell em to read all about it being to big here on TB...JustMyOpionion ;-) .
Do you think so? I went to their web site to read their warranty and they pretty much say there isn’t one. I did return a decoder this past summer because it was missing an LED and they did replaced it, but in this case the decoder works fine and is just over sized. I think I might have a Kato with that same decoder and I want to see if it will fit into it. If it does then I’ll probably use in another Kato. I’ve been thinking of starting a BNSF collection anyway. Someone else mentioned filling it down which I could do on the end but I don’t know about sides. If the tabs weren’t riveted on I could move them by melting a little solder, but if it fits into a Kato then I’ll be happy to keep it. I do need another one to replace the one I had for another Athearn that’s on back order. I hope I don’t have this problem again. The funny thing is as I was searching the net for more information, I came across an old post were a seasoned decoder installer was havening almost the identical problem and everyone was telling him that it does fit and a few were telling him to get a TSC and solder it. The final solution wasn’t discussed so I don’t know if he was having the same problem as I had.
Yes. Even though the electronics work, if it's oversize, then it's defective and should be replaced. If you wait and find the oversized decoder fits the Kato unit, great, everybody wins. You get a usable product and save Digitrax a replacement. But if it does not fit, then you should contact Digitrax for that replacement.
