Lionel 8351 Alco tune-up

My cousin asked me if I could fix his childhood Lionel train.   All it really needed was a good cleaning, but I figured I’d make a little tutorial so next time he can look after it himself.


Here we go, Ed!

First, remove the screw on the back of the cab.


Lift up the rear of the cab and disengage the tab at the front of the frame:


Put the shell aside (don’t lose that screw, either.


Next, remove the two screws on either side of the brush plate (the white plastic piece that makes up the top of the motor.)



Lift the brush plate straight up, slowly (don’t break the wires!)  Don’t be alarmed if the motor brushes (the copper colored cylinders) fall out.  Just don’t lose them.


The brushes are a wear part.  These are nearly at the end of their service life and will evenually need to be replaced.  I cleaned them slightly with a 1000grit sanding film.  The Lionel part number for the brushes is 8040-150.

Next, remove the armature.  Give it a slight counter-clockwise twist as you lift it and it will come right out:


The commutator face is the part that gets dirty the fastest. (I forgot to take a picture before I started cleaning it.)  The safest way to clean it is with a pencil eraser.  Just be careful about eraser shavings:


If there is any gunk accumulated in the slots, clean it out.  A flat-tip toothpick is a good choice.  (I’m using a thin piece of styrene I had laying on my workbench)


I used a paper towel to clean the old grease off the worm gear, and tweezers to pull any chunks of gunk out of the gears inside the truck (there wasn’t much, just a few hairs.)


There are quite a few different opinions on what the best grease is for toy trains.  I use Lucas Red N Tacky, because it’s safe for plastic gears and holds up well.


You don’t need a ton of it.  To be fair this doesn’t even need to be replaced every time, just when it starts to get gummy (which hopefully won’t be for another 40 years.)


Re-insert the armature (with a clockwise twist this time to seat it with the truck gears.)  Now is the tricky part:  re-installing the brush plate with the brushes in the correct spot:


It might take a few tries.  Once you get it all fit together, reinstall the two screws that hold the brush plate on.  Be careful about the one with the brass tab, when you tighten the screw it will want to rotate and touch the brush contact.  That would cause a short circuit and the motor won’t run.


Now appply a light machine oil to all 4 axles, and the axle of each of the power gears.  I use a product called Labelle’s #105, available at hobby shops.  A light gun oil would be ok if you have some.  “3 in 1” oil is not recommended, as it’s known to collect dust and become gummy.


That’s it!  re-install the shell (I found it helped to put the forward/reverse switch in the “neutral” position to get the cab back on) and re-install the screw on the back that holds it on.   You’re ready to roll!



2 thoughts on “Lionel 8351 Alco tune-up

  1. I have one of these also so the tutorial was helpful. my problem is with the three engines I have they will not run off the same transformer. one is clearly marked DC output and only one engine will run on that track. the other two will run on only the other track. my question is this. is this, pictured engine AC or DC.

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