Hello all!
I am having trouble with my Athearn RTR SD40-2 DCC quick plug equipped engine. I bought this train off of ebay and it seemed to run well in both directions when I got it but now it has a problem. The problem is the engine does not move very well in the forward position but in the reverse position it has no issues and goes from speed step 1 to 28 with no problems. In the forward position, I can turn the power up to speed step 28 and the engine barely moves and then stops. I can hear the unit humming like it it trying to go but it doesn't. If you help it along with your hand, the motor will try to turn but it still doesn't go very well. I have a digitrax DH123 decoder installed and I have reset the factory vaules but that did not fix the problem. I have even tried swapping out the digitrax decoder for an NCE one and it did not make any difference. I took the shell off and looked around but didn't see any kind of obstructions that would cause it not to move. Have any of you guys experienced something like this and how would I fix this problem? Thanks in advance!
Doesn't sound like a DCC issues based on what you've written, as you seem to have ruled that out. You mentioned looking around under the hood. Most important here are the driveshafts, which slip back and forth and can be adjusted if out of order somehow. Might be something to doublecheck.
You didn't mention the trucks, which hold theb gear train that transmits power down to the drivers. They're hard to see without disassembly, but you can pop the cover off the bottom and look at the final gears easily enough. Look for something out of place or a foreign object that may be affecting things.
Mike Lehman
Urbana, IL
Try putting the dummy plug back in (if you have one) and seeing if it does the same thing on straight DC vs. DCC. At least that way, you can eliminate the decoder part entirely.
To me, it sounds mechanical. I'd check for a loose worm clip or some solidified grease on the worms or worm bearings.
NSFAN216The problem is the engine does not move very well in the forward position but in the reverse position it has no issues and goes from speed step 1 to 28 with no problems. In the forward position, I can turn the power up to speed step 28 and the engine barely moves and then stops. I can hear the unit humming like it it trying to go but it doesn't.
I had that same problem soon after buying a Bachmann DC trainset. The locomotive would run on one polarity, and it was fine. (In DC, no matter which way you point the locomotive, it will go one direction if the polarity stays the same.) If I flipped the direction switch (polarity), the locomotive did basicly what you described.
For me, in DC, the problem was the power pack/speed controller. I sent the it to Bachmann, who replaced it free of charge. The second power pack/speed controller has been working flawlessly for five or six years now, and is still working well on my 9x8 foot layout.
Sheldon Beiler
I'm a'workin on the railroad.