Skip to main content

I'm interested in getting an older 726 and have a few questions about the various models.  I understand that the 46 model had a light bulb smoke unit, some sort of horizontal e-unit with spring return, and removable bottom plate for access to drive gear and axles. 


1.  Is there a modern smoke fluid that is acceptable to use.  Not interested in modifying the smoke unit. 


2.  How hard is it to keep the horizontal e-unit operating well. 


3.  What are pros and cons of removable bottom plate?  Seems like it would make it easier to work on? 


4.  Any other pros and cons to the 46 drive train?


Gene Dawson

Original Post

Replies sorted oldest to newest

As for smoke fluid, its use with the lamp type smoke unit was discussed here earlier this year.  You might want to search and see if you can find that thread. For 2, i have never had any trouble with the horizontal e-unit.  They work just fine.  On 3, there are ceramic insulators around each screw that holds the collector assembly on. These are frequently cracked.  This does not make any difference until you take it apart.  Before removing the collector assembly I would recommend that you have a spare set of these insulators.  There are nylon repros out there that would not crack like the original, but I have never tried them. On 4, I have never had trouble with the drive train, I run four '46 726s, but due to the dual worm drive, it could be very tricky if you want to press wheels on and off the axles. Getting the timing between the worm wheel teeth and the crank pins might be hard to do without hard tooling. I have ask about this in the past, but never got an answer.  The '46 726 is usually more expensive than the '47 to '49 version and parts for it are harder to find. I would suggest only getting the '46 locomotive if it has features you really want.


          The 1946 Lionel 726 Berkshire is a great engine.  The early 726 and the later 726s and 736s were different in several ways.  The two different style locomotives used different motors, different smoke generators, different E-Units and different boiler and frame castings.  The details of the body and gearing construction are not interchangeable.  


I have two of the early 726s and run them quite often.  They are not quite the pullers that the later 726s are and certainly are not as strong as the 736s with magne-traction. 


I have never used any type of smoke fluid in the lamp style smoke generators using strictly the old Lionel SP smoke pellets as well as the repros.  I do not know what affect, if any, fluid would have on the smoke bulb although recently someone posted on the forum that they placed some old asbestos insulation on top of the bulb and then applied smoke fluid and the engine smoked great.  For whatever its worth the old smoke bulbs did not produce a prodigious amount of smoke.  Nevertheless, I think they are kind of neat simply because they are different. 


The horizontal E-units in my 726s to date have not caused me any problems.  Having said that I will probably now be confronted with some.  I have cleaned the E-unit drums a few times as part of routine maintenance and have found these units no more difficult to work on than the regular E-units.  If need be, replacement units are readily available through Jeff Kane, The Train tender.


Maintenance of the double worm drive is really quite easy since the bottom plate completely drops out providing easy access to the double worm drive.  This kind of follows the pre-war build a loco concept. One thing to note here is that the cover plate assembly uses several white plastic or ceramic insulator bushings between the plate assembly and its screws.  These can and will crumble with age.  Without them in place the engine will not operate.  Again, replacements are available through the Train Tender as well as others.


As I have mentioned in other posts having an early 726 is kind of neat because it offers one a good look at early 1946 Lionel Technology. I think its fun to compare the technological progression in the manufacture of these engines so I have both the early and later versions.  The early 726 while not as strong a puller as the later models is still a smooth running engine and can pull a consist of four or five freight or passenger cars.


If you get one I'm sure you will be happy with it.  Good luck. 




Last edited by OKHIKER

Hi Gene,


First of all I love my 46 Berkshire, its a great running locomotive with very nice detailing. I have owned several of these locomotives and repaired even more over the last thirty years so here is my opinion. Others may agree or disagree.


1. I use super smoke in mine, only one drop at a time or it will leak.

2. The horizontal e-unit is the same as used in the Hudson's and is very reliable.

3. The obvious pro to the removable bottom plate is the ability to service the bottom half of the locomotive. The downside is that the ceramic insulators will crack if tightened too much, which can cause a short. Replacement insulators are available in ceramic and plastic if you break one.

4. The 46 has a double worm drive which makes both the front and rear set of drivers do the work. Even though the locomotive has nickle rims and no magne traction it is still a good puller.

Last point: If you buy a 46 and it comes with the original smoke pellets (plastic box with a lid that resembles a Ball jar) do not touch them, they are toxic.


Enjoy you Berkshire, I sure do!






Gene, when my e-unit started to hang up, I installed a QSI ACRU electronic reverse unit.  No buzzing.  On power up, initial movement will be forward.  I doubt these are still available---that's the catch.


If you purchase an engine with a working e-unit, it is unlikely you will ever have to replace it. The parts to renew them, with the exception of the special plunger and spring, are readily available. (They are standard e-unit parts) Used horizontal e-units are around too.
They sold lots of Berkshires and turbines in 1946.

Last edited by C W Burfle

Many many thanks to all the folks that took their time to reply.  OGR is absolutely the best forum I have ever used.  Useful, detailed and accurate replys quiclky.


I think a 46 model is what I will search for.  I have a lot of pre-war steamers and like the idea of something a little out of the ordinary.


Thanks again to all.



CW, the engine e-unit was working when I got it, and started hanging later, but why bother to work on it when an ACRU works better and quieter?


To each their own.

I prefer my trains to be 100% original, and don't care for electronics.

I find rebuilding e-units of any type to be a simple task.

The only specialty tool I use is an e-unit spreader bar (ST-303). I have other E-unit tools, but I don't find them to be helpful.

Maybe a quartering /loose wheel problem. Has the collector assembly been off recently. If it has, maybe one of the end wheelsets was replaced off by one tooth. Try running the loco with the side rods off. If this corrects the problem it would point to a quartering problem. As far as the motor running hot, has the engine been oiled and the grease been renewed recently?

Sorry for the delay as I was out of town. When I got home I tried removing the side rods and it didn't work. The spare motor I bought was in the mailbox. After a tear down I found that the pinion gear on the motor was sticking too far out and binding on the worm gear, swapping the motors did the trick. It now runs as it should.

I 'discovered' the smoke bulb Berk's a few years ago and now have three of them.  Beautiful details and strong engines.  One required cosmetic repair to the tender and new decals for the cab sides. I have never used smoke fluid or pellets, the room is large, but not large enough.  I like the 46', the year I was born.

I have a 46', 726.    I have upgraded my 726 to a high stack motor.   Runs well.  It has been described well.  I like not having an e-unit lever sticking out the boiler.   Also the front and rear wheels do drive, but the middle ones do little for pulling.  They have vertical play where the bearing fits in the casting.   They float up and down a little.   I call them gravity loaded not spring loaded.

47 and on the drive train changed allowing better precision in aligning all the wheels.   Savings in manufacturing also.

The Berkshires and the Hudsons is they drive one set of wheels with the motor and the linkage is active to  drive the other wheels.    On other designs the steam engine wheels are linked with gears and the linkage is along for the ride.

It doesn't puff as well as later units.   It does have a flapper to puff.  Since the original smoke pellets caused corrosion, the smoke bulb housing may have corrosion problems if too many were used.  The 1946 smoke pellets are toxic and a fire, corrosion and explosion hazard. (maybe if the whole bottle got hot)   Same stuff that blew up Texas City in 1947.  Which probably moved lionel to replace the smoke pellets with something else soon after.   Amonium nitrate is also a fertilizer base.

Last edited by VHubbard

Add Reply

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
Link copied to your clipboard.