I have an 1985-1986 talking silver rail express train set and it will move just a little ways and then stop. Has something happened with in the gear system?

SOURCE: Hello: Train won't move

CHECK FOR SWITCH ON BOTTOM OF TRAIN

SOURCE: New Bright Holiday Express Animated Train - figures do not move

Make sure you the wheels on the cars are actually rolling and not sliding (being drug down the track) Most of the animation is down mechanically as the set moves.

SOURCE: Holiday Express Train Set

We struggled with this just today...finally figured out that you have to twist the small piece right behind the bell on the top of the locomotive.

Testimonial: "Thank you! Now... how do you keep it on the track? :O)"

SOURCE: My New Bright Holiday Express train set is 10

Make sure your track is clean. take a green scrub pad and rub the track to clean off any tarnish

SOURCE: We are having difficulty turning

Here are a couple of resources from New Bright:
http://www.newbright.com/public/electric-train-faq

http://www.newbright.com/images/Manuals/384%20ws%20manual.pdf

There is no On/Off switch on the train. Power goes from wall plug to transformer, then from transformer to track clip, which must be attached to the track. A control line goes from the track clip to the controller. Mine has a green light just above the red On/Off button that will come on even if the engine and tender are not on the track. The tender does all the work, and must be connected to the engine and on the track. There are four sliding contacts between the tender wheels that provide contact with the track.