I have two internally identical Bachmann B&O F7s. Originally purchased as an AB pare, the B unit ran like a dream, with breathtaking creep speed, but the A unit wanted nothing to do with slow speed, so I returned both to Bachmann. When I got them back, not only did both units run fine, but the B unit now has a light inside! Go figure. However, the B unit now makes much more noise when running in either direction than the A unit. Does anyone have any idea as to why the B unit may be making so much more noise when running?
I would suggest you simply try a light lubing first. Place the loco upside down in a cradle and just lightly lube the trucks gears. Then take a 9 volt battery and touch it to the wheels. The lube should get carried up into the gear towers of each truck by running it this way. The next step would be to take the mechanism apart and then carefully re-assemble it making sure the bearing blocks are fitting into the chassis slots correctly.And very lightly lube at both shafts that come out of the motor and at any other turning point along the drive shaft. I recommend Spookshow's site for instructions on how to take it apart depending on which version you have. http://www.spookshow.net/loco/bachf7.html
