Recently bought 2 new Bachmann Spectrum two truck Shay locos from Thefavoritespot.com. Don't ask why I bought them - I don't know why.
One loco runs fine (slow, but I expected that). The other just makes a whirring sound, like the motor is spinning. No wheel or gear drive movement. Its not my track - happens exactly the same in a cradle. Any thoughts anyone? I seem to remember a thread describing this same problem some time back, but I could not find it.
Check the driveline for broken universals and cracked gears.
Also, do the wheels turn smoothly when you push the engine on the rails? If so, your problem may be in the gear stack in the boiler.
In either case, Bachmann support should be contacted.
-John
Bachmann's shay is notorious for gears stripping. I had to send mine back.
Bruce