Just picked up an Athearn GP 35 with the quick plug DCC. Put in a Lenz decoder, programmed and ready to go. When I ran engine, it has a jerking motion at slower speed, and loco seems to “wobble” left to right on slower speeds. Seems out of balance. What can I do to correct? Do I need to break it in some? Am I missing something. My only other Athearn runs fine. Please Help!
Thanks!
john
Did you run it on analog before you put the decoder in? It sounds like a mechanical problem, but I guess if the decoder was seriously pulsing power it could torque the motor enough to make the engine look like its wobbling. But I really think its mechanical.
Sometimes the older style Athearn diesels would either wobble from side to side when they ran or would have a pronounced “list” to one side. Remove the trucks and check for casting flash on the underside of the frame, particularily on the flat area around the pin on which the truck swivels. Also check the sheet metal plate on top of the trucks into which the frame pin engages, just inboard of the gear towers, to make sure that it sits level. If it doesn’t, you’ll have to disassemble the truck to improve the angle of the bend until it’s 90 degrees. Before reassembly, also check the area around the hole in the plate for burrs. I hope this is of some assistance: my layout (mid '30’s) is not yet dieselised.
Wayne
John,Remove the decoder and try this engine on DC if it runs without the fore mention problems then the problem will be in the decoder or CVs.
found the problem. it was the decoder. i appreciate the help from all!
john