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Centennnial Mogul

Started by bob kaplan, February 08, 2007, 07:27:45 PM

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bob kaplan

  Just purchased this engine (Cent. Mogul) last week.   Gave it a try and found that it was a beautiful performer...except--it really doesn't like LGB swithches.
   Behind the center wheel on each side of the engine, there are posts which extend down inside the rails to guide these center drive wheels and keep them aligned with the track so they do not drop down below the railhead.
   These posts seem to hang up on the LGB frog.  Logical that they be removed if this happens.  Which i did do.  But when i did remove the guides, the center wheel does indeed fall below the rail head once in a while (i use LGB 16000 curves and equivalent swithches--layout in my basement) and bind.
  A closer look at the guides revealed they were actually composed of a collar with a pin through it and then connected to the support structure.  If  the collar is removed and the pins inserted from the top instead of the bottom of the support, then engine does seem to operate a bit smoother through the swithches.  But still not as nice as Connie or Annie.  (Am i making any sense here??)
  i know i read of people experiencing this, on the old form, but never paid attention to it, since i never thought i would purchase this engine. 
  Wondering if others found solutions for a smooth performance through the LGB switches.


Yes, I have!
The rear journals (third axle) on mine were upside down.
This allowed the center drivers to "fall".
I have 1600 in the shed (too cheap to throw the stuff out), and mine does NOT fall through anymore.
I had the "procedure" somewhere, let me see if I can find it.



Found it!  May of 2004:

This has been driving me nuts (more nutz than usual) for a long, long time.
I've seen it, where the center driver drops off the rails on a curve, and read about it numerous times by others.
So, last night's operating session, I decided to drag mine out and run it.
Drove me crazy again.
So, I tried glueing .060 shims on top of the lead drive axle journal, to keep the front of the loco from fully dropping.
That worked, no more "catching" of the drivers on curves, could see the angle of the running board. Not good.
Today, after all the other things I had to do, I decided to tear it down and fix it.
First, I grabbed my big framing square, popped the temp shims out, depressed the lead driver axle down, and checked down all three axles on one side.
Not pretty.
I checked the running board angle, still angled up, even without the shims in place (center of board to benchwork with loco on rails).
Then, I flipped the loco over, pulled the bottom cover on #2 and #3 axles, removed the crankpin bolts on #3 axle, and pulled #3 axle out of the chassis.
Then I inspected it.
First, I noticed the top (top being away from the part that contacts the rails) of the journal has a small pin that sits into a hole in the top of the frame.
Okay, now we're oriented.
Pulled the driver caps, screws, and pulled the wheels off (this is a good time to check your back-to-back for G1MRA 1.575" and install washers between driver stubs and contact drum) and looked at the journal boxes.
I pulled the boxes, held them together, with one pin up, one down, and there is about .040" offset in the bearings.
So, I re-assembled the journals and drivers (look at the boxes...there is a "flat" side and a "humped" side...."hump" to driver....keeps the drivers from rubbing on the frame) and dropped the assembly back into the frame with the pins facing out of the chassis.
Put it all back together and on the track, running board is dead level, and center driver......I can just see light between it and rail.
You can tell how yours is put together without taking anything apart.
Rotate the drivers so you can see through the spokes of #3 driver (either side) at the bottom of the journal box.
You will always see a round peg just forward of the centerline, about 1/8" o.d., and a similar square peg just aft of the centerline.
If yours is put together with the pin down (high cab) the pin will just be visible between the square and round pegs.
If you want to fix it for a test, pull the rods off #3 axle, pull the bottom cover (8 screws) lift #3 axle assembly out, rotate journals to correct position and drop back in. Re-assemble and test.
Let me know what you find.


Where can I find a picture of this Mogul

bob kaplan

Thanks for taking the time to send the "fix" for the mogul.  It is going to take some time to sort through your directions...with the engine in front of me  for sure, before i get the "courage" to try to solve the problem.  But i will give it a try or a least a very serious look; but pulling wheels and correct quartering of the parts make me very nervous.

Do you have any idea if they were all incorrectly assembled this way, or was it just a few?  If i get the thing apart, and get her back together, can she be sent to Bachmann service for proper assembly?

Thanks again for your help.

bob kaplan

  i pulled the bottom plate off the Mogul.   

1.  The electrical wires for the motor run to the journals for pick up i think.  Do these wires need to be de-soldered before doing any work on the #3 driver?

2. i am not sure if i comprehend your procedure correctly.  Do the journals, wheels have to be removed from the axle to complete operation?

That is as far as i have got up to this point.

bob kaplan

After removing the side rods from the third set of drivers,  i lifted the journals and wheels/axles out of the chassis (there is a "bunch" electrical stuff there!) and rotated the journals 180 degrees without detaching electrial contacts.  Put the unit back in the chassis and reinstalled cover plate and side rods  (Probably not in accordance with your directions completely) but it works!  Center driver does not drop below rail head and engine operates well.
   Thanks for your help!!!


Aristo switches as well :-[

Is there a parts diagram on the web somewhere?


Sorry, Bob, I was gone until tonight.
As you can see, it wasn't hard.
I have no idea if all, some, or a few were that way, but this fixed the ones I've worked on.
Quartering is automatic, as long as you're not 180° off.