1) Add weight in the nose or over the drivers if possible. First test it with some weights taped on externally if possible.
2) How are the traction tires? Try new ones?
3) If you exchange the switches and the problem moves with the switches, you know the problem is with that particular switch. If the problem remains in the same location, the adjacent tracks are the problem. That still might not rule out the locomotive.
How about some closeup pictures of the underside of the locomotive, the tender drawbar/tether, and the switches?
MELGAR
