After many years of repairing Lionel and other makes of classic toy trains, I’ve found that most locomotive failures are electrical in nature. Surprisingly few are the result of mechanical shortcomings.
For electricity from the transformer to do its work, it must be properly directed to the two major components – the motor and the reversing mechanism (commonly called an E-unit). The thousands of Lionel trains made during the 20th century are relatively simple machines, and the problems they develop usually aren’t difficult to ascertain and successfully repair.
In this article, I’ll address postwar and early modern-era Lionel locomotives powered by open frame (“Pullmor”) motors. Modern locomotives with sealed can-type motors and complex circuit boards usually require the services of a qualified technician. However, some of the following suggestions, such as tracing loose wires and adding proper lubrication, apply to these units as well. Let’s get started!
We’ll look at the most obvious difficulty first. If there is power to the track (use a test light to be sure) and your engine is stone cold dead – no lights, no hum from the E-unit, and not a spark of life from the motor – the problem is almost certainly an open circuit. This means electricity isn’t going where it should. Look for the following conditions.
Broken or loose wire. At right is a diagram of the wiring for a typical locomotive. Two wires from the reverse unit connect to the brushes. One is attached to the field of the motor, and the other connects to the pickup roller assembly. Examine each wire to determine if there is a loose connection. Most locomotives have an additional wire or wires for the headlight and/or cab light, and many diesels have a built-in horn circuit, but these wires are not involved in making the motor run. If the headlight doesn’t work, and you know the bulb is not burned out, look for a loose or broken wire to the pickup roller assembly. Also check the ground connection from the field.
If the transformer overload light comes on after you’ve advanced the throttle or the circuit breaker trips and cuts off power, there is a short circuit. What’s a short circuit, you ask? Any circuit in which the electricity can return to the opposite pole of the power source without passing through the device it is meant to activate. Electricity will always follow the path of least resistance, bypassing a lamp or motor when another route exists. Some of the most common causes for a short circuit are as follows.
Loose wire contacting frame. Be it the result of a failed solder joint or an excessive tug when removing a part, a loose wire touching the frame or another wire connection point will cause a short circuit. Determine where it belongs (refer to the wiring schematic on the previous page) and reattach it. This probably is the most common short circuit and the easiest to remedy.
Also, sometimes the washer inside the socket becomes bent or otherwise distorted, causing a short circuit. It should be replaced if you can’t bend it back into shape without breaking it.
Loss of power
Your locomotive may light up and move forward sluggishly, yet it seems to lack power. It may run with a jerky motion, stall completely at low voltage, or be unable to attain normal speeds. To operate properly, the motor must receive an unimpeded amount of electricity, and there must be nothing that causes the mechanism to bind or to develop unnecessary friction. Let’s first examine the electrical causes for this type of failure before we explore other possible mechanical issues.
Improper lubrication. Using the incorrect type or an excessive amount of lubrication can interfere with electrical transmission. When applying lightweight oil or grease, be sure none of it comes in contact with the brushes or commutator. Also be sure the wheels are clean and free from oil or grease. A little bit of lube goes a long way.
Although you can attempt to adjust the tension of these springs, it’s probably best to replace this key component.
If you don’t have a meter, use the two wires from a transformer to test for this condition, with the throttle set at about 12 volts. There should be no sign of sparking. If there is, you can obtain replacement armatures from parts suppliers.
In the absence of a meter, use two wires from a transformer with the throttle set at about 12 volts. There should be a strong spark at all three segments. If there isn’t and you can’t find any broken wires, contact a qualified repair shop or obtain a replacement armature from a parts supplier.
Friction and binding
Following are the most common mechanical problems that interfere with smooth operation. The foremost cause of poor performance is friction from lack of lubrication. Consult the instruction sheet that comes with each locomotive for the proper application of oil and grease, and lubricate very sparingly. Too much oil or grease attracts dirt and hastens the reoccurrence of these problems.
If you don’t have an instruction sheet, the following general guidelines apply.
Dry rods. Place a drop of oil on all moving parts of a steam locomotive valve gear and side rods. Make sure no oil migrates to the wheel treads. Wipe everything with a soft absorbent cloth, such as an old t-shirt, when you finish.
Binding side rods or valve gear. If a steam locomotive seems to hesitate slightly with each revolution of the wheels, the most common cause is a bent rod or incorrectly installed rod screw. Remove the rods and valve gear, and test the locomotive on the track. If the problem has disappeared, reinstall the rods one piece at a time and test after each one is attached. When the problem reappears, the last piece you installed is the source of the binding.
Mystery metal parts. Examine the gears and wheels for foreign objects. This problem most often occurs with Lionel locomotives equipped with Magne-Traction.
Worn or wobbly gears. Finally, inspect the mechanism for gears that are worn or loose on their shafts. This problem is especially prevalent on Lionel’s postwar Alco diesel locomotives. Gear replacement requires specialized tools and is best left to a repair shop