Mechanical E-Unit Won't Cycle After Drum Change

It sounds like there is a short somewhere. Remove the e-unit and check the wire from the rollers to the e-unit, that it is not shorting to the e-unit frame or engine frame. Check to make sure the wire insulation is intact and not chafed. Also make sure the contact fingers are not bent out of shape, and that the drum is intact and not broken. Insure the metal bottom shield is not touching the contact fingers.

Larry

Looking at the E-unit, I think the problem is the drum. Not only is it not spinning, but it seems one end that secures to the wall has broken and is leaning downward. Everything else seems to be where it should, though I might have to redo one of the wires to the pick up rollers, as the heat seems to have melted some of the insulation.

Yes, the drum will need replacing. For some reason the clear plastic versions are known to break at the drum axles. The metal part of the drum is grounding on the e-unit frame causing the problems.

watch out, some repro drums are smaller,  I think its the pins, 

replace the drum

Mikado 4501:    You are experiencing  "Crystal Drum Syndrome".  These clear drums, while pretty to look at,  are prone to craze and self-destruct on their own.  The clear plastic is known as  "virgin" and has very little strength.  I bought a few dozen of these drums when they first were used,  and they are self-distructing  as I write  in the storage drawer where they reside.

                            The best drums are the older Corp. light green drums, if they can be found. They were the last made by the old Lionel Factory in Hillside, N.J.     Like they said, change it out. 

          Also, look out for the real white drums,  as the metal contacts on these drum are irregular with narrow and wide parts.  These parts a formed from a theta type stamping (circle with a line thru the center) that is drawn into shape.  Many are not evenly done causing the  four finger contact to sometimes not get off a contact when the drum rotates.  Rotate the drum in your hands, if you can, before purchase to be sure that the contacts are evenly formed all the way round the drum; it is pretty obvious when they are not good.   Hopes this helps.  Dennis M.

Also, look out for the real white drums,  as the metal contacts on these drum are irregular with narrow and wide parts.  These parts a formed from a theta type stamping (circle with a line thru the center) that is drawn into shape.  Many are not evenly done causing the  four finger contact to sometimes not get off a contact when the drum rotates.  Rotate the drum in your hands, if you can, before purchase to be sure that the contacts are evenly formed all the way round the drum; it is pretty obvious when they are not good.   Hopes this helps.  Dennis M.

The white drums with which I am familiar were made by one of the folks who was in the reproduction parts business. Even Lionel was purchasing drums from him at one point. (He told me so).
In my experience, the older ones were of reasonably good quality, but over time the quality suffered. The last ones I purchased were bad enough that I went on a hunt for NOS drums. Some of the ones I found are tan / light brown.

Could the difference be due to wear on the tooling?

You are experiencing  "Crystal Drum Syndrome".  These clear drums, while pretty to look at,  are prone to craze and self-destruct on their own.  The clear plastic is known as  "virgin" and has very little strength.  I bought a few dozen of these drums when they first were used,  and they are self-distructing  as I write  in the storage drawer where they reside.

I have a few of those drums, and a few NOS complete e-units with those drums installed. I wouldn't install them, but they are interesting to have. I've run across a few modern era locomotives with clear drums that had the nibs broken off.

Thanks for the tips everyone. I've never seen a green E-unit drum so far. The most common colored drum I see is red, though I have seen a few black ones here and there.

I'll be making a drop at the Train Station in Mountain Lakes this weekend to see if they have one on hand. If anyone has anything old Lionel related in the parts department in Jersey, it would be them.

The Train Tender had red reproduction e-unit drums made, and still carries them. The manufacturing parts dealers usually wholesale parts to other parts dealers, so many will carry them.  I have not examined a sample.

Lionel did make red drums at one time. I don't know of anyone who has studied the drums carefully enough to identify when various colors were made / used. There was an article in the TCA Quarterly cataloging the colors, but I don't think it included dating.

Well, I found a new drum (and some extras) at my favorite service station, the Train Station in Mountain Lakes. I was able to pop the drum into the E-unit, and readjust the fingers on the two contact boards making sure that they're touching the drum.

The thing is even though the E-unit solenoid engaged the pawl and clip in the drum cog teeth, the engine would not step out of neutral. This is really scratching my head, because I thought I got everything back in the right spots...

These are the white drums BTW, but they felt like they were evenly done.

Make sure the contact fingers are straight and touching the drum properly and with enough tension. Replace the contacts if necessary.

Check also to make sure the E-Unit and motor are wired properly. Refer to the wiring diagram on the bottom of the page here.

Larry

Is the drum actually rotating?

Dale, yes the drum is turning with every cut of power.

The wiring is correct, so maybe the contact fingers aren't straight enough, even though they're all touching the drum.

Two thoughts:

1 - Sometimes those white drums have a very thin film of plastic on the metal contacts. If so, the film has to be removed.

2 - it looks like the contact below the green wire may not be making contact with the metal segment on the drum. I have had white drums where the registration between the teeth and the position of the metal segments is off. I have also had white drums where the metal parts that are supposed to make contact with the center fingers is crooked. When I run into this I just set the drum aside and use another one. It is also possible to modify the contact fingers to work with the drum, but there is a good chance of ruining the fingers, so I don't really recommend that option.

If I can lay my hands on a sample bad one, maybe I can get a picture or two posted.

I have an original 1950's Lionel drum I can sell you, one of the green ones. Shoot me an email.

I've had similar problems with repro drums that had some kind of coating on the metal bits. So now I give them a light going over with a 'Brite-Boy', and a shot of contact cleaner, before installing and haven't had any more problems.

MIKADO 4501 :    When looking at the photo of your E-unit, I noticed that your four-finger contact is one with the wiring colors switched.  Traditionally, the older Lionel Corp. color wire layout was , looking from right to left:  1st terminal was  BLACK, power into the E-unit;  Next, center terminal was  BLUE ( is always a brush contact as is the lower  YELLOW );  and finally the extreme left was  GREEN going to the motor field connection.  Your  Blue and Green wire are reversed as far as color goes.  No matter what the color of the wire (could be all black for that matter) the positions to where the wire goes is always the same, with a very few exceptions.  In early Lionel MPC times, many of their E-units were made with white wire with color traces, and also with the reversed  Blue/Green wire arrangement, I believe that LTI finally went back to the Lionel Corp. color scheme.

          As others have stated, there is sometimes a film on the drum that needs to be buffed off, then wiped down with a cleaner.  I use an automotive plastic scrungie to clean the drum, then I wipe it off to clean any plastic residue that may have been left behind.

          An additional note is that you do have a small bit of adjustment to the drum rotation thru the pawl assembly (the part that drops down by gravity to engage the drum teeth and rotate the drum).  A slight bend can be made to the pawl at the bend area to move the drum a bit more for better contact position of the fingers on the drum contact.  Remember your high school;  math, there is only one  Locus of points on the fingers that actually contact the metal on the drum surface. Sometimes the finger is just hitting the drum metal contact on the edge near the plastic, so it needs a slight movement more to be on target ( this could also help with those drums with off registration of the contacts with the drum teeth).

          One last reminder about the finger pressure. It is important the the finger pressure have good tension, but not so heavy that it restricts the free movement of the drum by the pawl.  Too much pressure will cause the drum to take a moment longer to function/rotate,  and you will see your loco want to lurch in movement before the new position on the E-unit is reached.

          Okay, I've prattled a bit long here, but hopefully the info I and others have related will help you finally fix your E-unit to operate correctly and run your loco.  Dennis M.

 A slight bend can be made to the pawl at the bend area to move the drum a bit more for better contact position of the fingers on the drum contact.

True, but I'd rather not bend the pawl to make up for a poorly made repro drum. Turns out I do have a sample red drum from Train Tender. I haven't installed it, but it looks good.

Another related comment: a few years back, I picked up a small lot of reproduction two finger contacts. Turned out the hump in the fingers that contact the drum were not in the correct spot. In order to use them, the contacts had to be flattened out, and the humps reformed. I think I used one or two. When I run out of good contacts I'll worry about them.

If you like the loco, and plan on keeping it for a while, why not update it with a Dallee 4 amp reverse unit? It has a very small footprint, and anything you do to install it is reversible, and you can usually leave the original in place, in case you want to sell the loco. The only difficult part is unsoldering the field wire that is soldered to the motor case. Otherwise, just follow the clear directions in the packet, there are even options for directional lighting, if you wish.