I just received a new Spectrum 2-10-2 DCC/sound locomotive which will be my B&O coal drag. I test ran it and as it moves down the track, it "rolls" back and forth from one side to the other and is "jerky" in forward and reverse directions. Why is it doing this?
timber
Either one or more drivers are out of quarter. A link is binding. or if it has traction tires one of them is either not seated right or out of round.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Check that you don't have a loose screw in the valve gear.
Check that you don't have a loose or bent rod in the valve gear.
Check that you aren't missing a retainer plate, or an axle bearing that would allow axles to "dance" in their frame slots. I know it sounds ridiculous, but I have purchased steamers in the past and found that an axle bearing was missing (it was an expensive brass engine).
Be advised: valve gear is delicate. A loose screw destroyed my P2K (I know this is a Bachmann Spectrum 2-10-2 you are concerned with) 2-10-2 at 40 minutes run time. The loose screw bent a P2K main rod, and even though the selling store fixed the bent valve gear, my P2K 2-10-2 never ran right again. Walthers graciously provided a replacement engine, which I resold at a loss, not wanting to have any more issues with loose screws backing out and bending the lightweight P2K valve gear.
I also have a Spectrum K-4 that arrived "brand new" with a bent main rod. A screw was loose. I tightened the screw, and straightened the rod as best I could without removing it from the engine, and it runs just fine, though a tiny kink is still visible in the main rod. Because this engine does not have sprung drivers like some engines, and because it has rather large diameter drivers, it does do a little "dance" down the track (occasionally making a rail pounding noise), but has performed very reliably for me. The screw into the wheel has remained tight.
John