LW transformer

Yes, you can repair it using the diagrams from Greenberg's Repair and Operating Manual for Lionel Trains and parts from Jeff at The Train Tender.

Dave,

  Check the voltage at various points around the layout with no trains on it when your problem develops, then disconnect the wires from the transformer to the track and check the voltage at the transformer itself. The 2 sets of readings should be the same. If the transformer only reading is higher, then there is a problem in the track. If the readings are the same, then there is a problem with the transformer. It could possibly be a bad connection inside the transformer. With the transformer unplugged, check for bad or broken binding post studs inside the case. Also check the circuit breaker; it could be  opening a bit, or the points could be pitted or dirty. Try jumping it to see if normal voltage returns. Clean the surface of the coil and the wiper. Make sure the contacts of the reverse switch are clean and make solid contact with each other. Not much else can cause a loss of voltage.

Larry

Dave, when you say it "drops off," does it gradually decline or stop suddenly? If gradually, does it eventually decline to zero or drop a certain amount and then stabilize at a lower level?

Martin

What train Larry said. Plus look at the direction/horn brass reed contacts for burning or not making good contact. Some of the old LW's have a few small rotted insulation wires in them, watch for that.

Rob

Have you tried other engines to eliminate the possibility that it's not a problem with the engine? Did you actually check the voltage to see if it did drop or does the train just slow down without reason? If you did check the voltage, was the train still being powered by it, or did you take the train off and then check the voltage?  Does it happen regardless of how much load is on it? Does the transformer get hot when the voltage drops off? Is it just powering the train, or are there other things hooked up to it too?

If it's the same engine and it's not a can motor, I'm leaning toward a dirty armature with a bunch of crud between the segments. As the engine runs, the crud gets warm, melts a bit, and provides a path for the electric to short across the motor, causing the train to slow. It gives a nice illusion that the transformer is failing.

If it's not the same engine each time, then that's not likely the problem

J White

It drpos off slowly as the transformer and engine warm up, does not go to zero the just runs slowly.
Larry I will check it out using your directions.

J White, it is an engine with a can motor, the transformer does not feel overly hot just warm. Have not checked the voltage with the engine off the track.

Thanks for the replies

Dave

The engine is a Lionel 103 steam w/smoke.

I tested the voltage around the track,no trains, and it's consistant, with the transformer disconnected the voltage is the same.

I followed the directions from Larry when testing, so I guess it's the transformer.

The next step would be to open it up and look for problem areas.

Thanks again for the help.

Dave