I have two MTH GP7 diesels (20-20246-1) lettered for my railroad of choice, the Pittsburgh & Lake Erie. My layout uses postwar style tubular track and RossPlate switches.
These diesels regularly stall when going over the RossPlate switches. They hit a particular spot, and stop dead. (Partial spoiler alert – the problem was NOT the switches.)
Over other parts of the layout, the engines run fine. I originally thought the problem was with the engines so I spent time checking the motors and looking for bad solder joints or some mounting problem.
I finally realized that one truck was actually lifting slightly and loosing contact with the outer rail causing loss of power to the engine. But how could that be? This engine has two two-axle trucks for a grand total of 8 wheels that contact the outer rails.
Or do they?
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