I have the same diesel and haven't experienced that problem. I looked at it and there doesn't appear to be much clearance between the wheels and the sideframes. You might try prying the wipers with a thin screw driver so they make better contact with the wheels. Not want to take a screw driver to mine, you may be able to remove the side frames and then go after the wipers.
My Atlas HH660 with DCC sound, which has about two hours run time on it, has started dieing when it starts around a curve. I pulled the shell and all the wiring looks good and then I looked at the trucks. It appears the side frames and metal wheel wipers are just enough wider than the wheels so that on a curve the wheels on the outside of the curve pull away from the wipers. I laid the frame on its side and using my volt/ohm meter applied a very slight pressure to the wheels on the side of the same truck and also on the same side forward and back truck wheels and electrical contact is lost. The wheels are in gauge using my trustie NMRA gauge. Could the truck side frames and wipers have spread just enough to lose contact, is this a common problem, and what is the solution? Thanks for any suggestions.
Capt. Brigg Franklin CEOPacific Cascade Railway in HO GaugeRoute of the Northern Star
Capt. Brigg FranklinUSCG Licensed Marine OfficerCertified crazy train chaserCEO: Pacific Cascade Railway