athearn SW7 loco problems

[ShaunCN]

I have an athearn SW7 loco that runs fine backwards but when I try to run it forwards it needs more power from the power pack. I have checked and rechecked the entire unit from cleaning the weels to looking for flash on the gears(whic i didn't find any) I'm wondering if one of the springs that go in the top and bottom of the motor may be too tight casing it to need more power(this is what i read somewhere) Please help me get this switcher back up and running. [:(]

[Anonymous]

Brush springs (the part you're referring to) shouldn't need adjusting - just run the model for a while to bed in the brushes. Mine had similar problems for a while. I've modified the power pick-ups by replacing the springy metal strip that takes power from the trucks to the top of the motor with a couple of bits of flexible wire, which seemed to help with pick-up. Try oiling the motor bearings and greasing the gears (use plastic-safe grease), then run the model for a while. Just check that nothing is rubbing on rotating parts inside the loco.

[Eriediamond]

Shaun, I think Railroading_brit hit the nail on the head about the part of the brass strip that clips to the top of the motor on your loco. I would suggest before doing any drastic modifications or teardowns to try this: pop that strip or strips (sometimes there are two) and make sure they are clean and the tabs on top of the trucks that they make contact with are clean and shiny also. Reassemble them and make sure the brass srips have enough spring tension that they make a good contact with those tabs on the truck tops. This should correct your problem. This should become a part of your routine maintainace proccedure in the future. Why? Because those brass strips are solidly clipped to the motor frame and the torque from the motor causes it to rock back and forth as you change directions. The combination of this rocking and the swivaling of the trucks causes arcing and carbon build up between those brass strips and where they contact those tabs on the trucks. I wish you luck, Ken