I have a question about a 1980s lionel engine when I give power to the engine the light comes on and e unit hums but the motor hums and jitters move a little then stops.i stop the power then neutral and then reverse it runs a little better in reverse but no forward I’ve oiled and cleaned it. I’ve also had this happier to my postwar 628 switcher e units are both fine there both diesels and only want to run in reverse any got any ideas?
If you have not done it already, you need to disassemble the motor, clean and lubricate it. Use naptha (lighter fluid) to clean the brushplate, brushes and springs, and the commutator of any gunk. Replace worn brushes or springs if necessary. Oil the bottom bearing for the armature, reassemble the brushplate, and oil the top armature bearing. Grease all gears, and lightly oil the axle bearings.
Make sure the e-unit is clean also, and the contact ‘fingers’ are making proper contact on the drum, are not damaged or worn through. Some people use spray contact cleaner on the drum and contacts to good effect, while others prefer to disassemble the e-unit for a better cleaning and overhaul.
Clean the wheels and pickup roller(s) with naptha, and make sure the track is clean also.
Larry
May check the armature. If is it lifting up too high when it starts to turn, tighten the top set screw. Seen them rise too high and bind. Comes from lots of use and/or no oil on top of armature shaft [only a little drop will do].