# Who Is Familiar With Marx Diesel Loco's?



## NAJ (Feb 19, 2016)

Trying to get this Locomotive running, just a quick question...

Does power for the motor come from the front or rear truck?


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## Cycleops (Dec 6, 2014)

I'm not familiar with Marx except Groucho but here goes. I assume you mean power pick up. If you can find brass wipers on the trucks that's where the power comes from, no wipers no power pick up. It looks a very rudimentary design so maybe they just come off one truck.


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## mopac (Feb 24, 2011)

I am thinking one side of power is from one truck and the other side of power
is from the other truck. In your first pic. it looks like all wheel sets have metal
wheels on one end and plastic wheel on other end. In your pic all metal wheels are on one rail. It seems one truck would have metal wheels on one side and other truck
would have metal wheels on the other rail. Is there any chance one set of wheels are laid out wrong?
I just don't think all metal wheels are on the same side. There is only one wire to motor so other side
of power is from the frame.

That might be why you can't get it to run. 2 metal wheels on one rail and 2 metal wheels on the other rail.
Of coarse not opposite on same truck.


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## NAJ (Feb 19, 2016)

There are pickups on all four wheels.
The motor is on the rear truck.
The metal wheel chassis comes up through the plastic truck and the motor sits in a metal housing that is attached to the metal wheel chassis.
The motor has a single wire that is soldered to the metal housing and another single wire is soldered from the top motor support to the front truck metal housing that is attached to the metal wheel chassis the same as the rear is.

This image shows... 
1)The metal wheel chassis's with the pickups on all 4 wheels.









This image shows...
1)Where metal wheel chassis comes through and attaches to the metal motor housing.
2)Where motor is soldered to the motor housing
3)Single wire soldered from rear motor support housing to front truck metal wheel housing support assembly.


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## NAJ (Feb 19, 2016)

mopac said:


> I am thinking one side of power is from one truck and the other side of power
> is from the other truck. In your first pic. it looks like all wheel sets have metal
> wheels on one end and plastic wheel on other end. In your pic all metal wheels are on one rail. It seems one truck would have metal wheels on one side and other truck
> would have metal wheels on the other rail. Is there any chance one set of wheels are laid out wrong?
> ...


I was not sure about the wheel setup myself so I found an image of the underneath online and verified I had it correct.


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## mopac (Feb 24, 2011)

Your last pic shows 2 metal wheels on one rail and 2 on the other rail. It will be impossible
for engine to run with 4 metal wheels on one rail and none on the other. You have to pick up power from both rails. Last pic shows a traction wheel on one rail and the other
traction wheel on the other rail. Humor me and try it. All 4 metal wheels do not go
on the same side.

I don't know a thing about marx locomotives but I do know a bit about model trains in general. If you have all
4 metal wheels on one side she will never run.


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## NAJ (Feb 19, 2016)

mopac said:


> Your last pic shows 2 metal wheels on one rail and 2 on the other rail. It will be impossible
> for engine to run with 4 metal wheels on one rail and none on the other. You have to pick up power from both rails. Last pic shows a traction wheel on one rail and the other
> traction wheel on the other rail. Humor me and try it. All 4 metal wheels do not go
> on the same side.
> ...


A little miscommunication here, in the first pic showing the train disassembled with all of the parts laid out with all 4 metal wheel flanges on the same side is not the way the wheels were configured when it was assembled, that is just the way they were placed when the pic was taken.

Here is the present wheel configuration.


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## NAJ (Feb 19, 2016)

So you are saying that power for the motor is coming from both the front and rear trucks?
This is probably something simple and I am over analyzing it.

1)Point A is where the motor is soldered to the motor support housing
2)If I apply power to point B (either post) and Point C (either post) the motor runs.
If I reverse polarity the motor spins the other direction. (Basic DC Operation)

I totally understand electricity principal and theory and realize we need a + and - to complete the circuit, however...

Point A is the only spot where power comes into the motor. 
The rear motor support housing is connected to the rear wheels through the metal wheel chassis.
The front truck is connected to the circuit the same way, the metal housing is connected to the metal wheel chassis and the front assembly is connected electrically to the rear by a wire that is soldered from the front housing assembly to the rear housing assembly.

That is still only one connection at the motor.
This is where I am confused on where power comes from.


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## mopac (Feb 24, 2011)

That is good you tested the motor and it runs. 
Motor ran when power put to B and C. So those
are the 2 motor terminals. You need to get power
to them when assembled. I think that wire from
frt truck should go to point C not to engine housing.
I think point B is getting one side of power from the
truck under the motor and you need to get power
to the other motor terminal from the frt truck. That
would be the wire. I think the wire needs to go to
point C.


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## NAJ (Feb 19, 2016)

The way I listed it is the way it was assembled when I took it apart and it appeared to be all factory.

There was another wire running from the bulb to...???
I cannot remember.


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## mopac (Feb 24, 2011)

I tried to google a photo of marx wiring and nothing came up.
I know you need to get 2 sides of power to motor. One side to
B and one side to C and that puppy will run. Seems like it would be a dead short
To have B soldered to motor case and then the wire from front truck
soldered to motor case also.

Is the frame metal or plastic?


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## NAJ (Feb 19, 2016)

The Wheel's, Wheel Chassis, Motor Housing (Rear) and Ballast Housing (Front) are metal. 
The Trucks, Lower Frame and Shell are plastic.

When I got this loco last Christmas it ran but not very well.
I took it apart, cleaned, re-soldered and lubed, it ran well on the test track in reverse but was "jumpy" going forward so I disassembled it again.
Found the motor housing was loose on the truck and torqued to one side going forward causing the truck to want to turn.I am now verifying every metal mating surface where current has to flow is clean/tight with good continuity (0 ohms resistance), from all wheels to the wheel chassis's to the motor and ballast housings to the motor and all points in between and that the motor housing is secured to the truck so it will not move.

Verifing good electrical connections is the reason I am curious how current flows to the motor on this setup.


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## mopac (Feb 24, 2011)

I just don't see power going to motor terminal C. 
And I think it needs to come from front truck.

Motor is on rear truck?


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## NAJ (Feb 19, 2016)

Terminal B is connected to Terminal C under the center plate.
I needed a magnifying glass to see it so do not know if you can see it in the pics.


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## ggnlars (Aug 6, 2013)

HO drives in those days originated from only a few sources. Marx, Lionel & AC Gilbert were all big in the O guage Tin plate toy trains. 
HO started in the thirties. Initially, they all made their own trains. These were basically steam engines with very few very early diesels to replicate. During WWII toy train production stopped. It started up again after the war. 
The new items, diesels tended to be made by Varney and sold to others for their products. The drive your showing is a version of a Varney/Baker drive. It probably is from the early fifties. This is based on the plastic shell. Before that, they would have been all metal. 
You see this same fundamental drive and shell on several different manufactures diesels from that era. It uses a Pittman style motor, the best at the time, to drive both trucks. The plastic shaft drives the non powers truck. Electric power come form both trucks. The right side of one and the left side of the other. The part details differ from various manufacturers versions. Remember these were primarily toys and cost was a big issue. Marx was known to be the "cheapest" in the market. Not necessarily the best. Usually you can get these to run almost like new with some patience. Keep in mind new in 1950 was different than new in 2016. It can run pretty well for a 60 year old item.
Larry
www.llxlocomotives.com


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## NAJ (Feb 19, 2016)

ggnlars said:


> HO drives in those days originated from only a few sources. Marx, Lionel & AC Gilbert were all big in the O guage Tin plate toy trains.
> HO started in the thirties. Initially, they all made their own trains. These were basically steam engines with very few very early diesels to replicate. During WWII toy train production stopped. It started up again after the war.
> The new items, diesels tended to be made by Varney and sold to others for their products. The drive your showing is a version of a Varney/Baker drive. It probably is from the early fifties. This is based on the plastic shell. Before that, they would have been all metal.
> You see this same fundamental drive and shell on several different manufactures diesels from that era. It uses a Pittman style motor, the best at the time, to drive both trucks. The plastic shaft drives the non powers truck. Electric power come form both trucks. The right side of one and the left side of the other. The part details differ from various manufacturers versions. Remember these were primarily toys and cost was a big issue. Marx was known to be the "cheapest" in the market. Not necessarily the best. Usually you can get these to run almost like new with some patience. Keep in mind new in 1950 was different than new in 2016. It can run pretty well for a 60 year old item.
> ...


Thank You Very Much, I Love history lessons like that.
So power comes from both the front and rear wheels.
I am now taking my time with the reassembly, part of the reason is that the 4 metal tabs on the wheel chassis protrude through the plastic truck housing and then are bent over to hold the metal housing in place and provide an electrical path from the wheels to the motor.
Those tabs broke off from unbending them and bending them back so I have to flow solder down the hole where the tab would have protruded so taking it apart again is not as easy.

Although this may have been a toy when it was made what I did notice is that this loco appears to have been made to be easily disassembled for maintenance and cleaning, nothing like trying to repair and disassemble a 1970's/1980's Bachmann loco which I have miserably failed at twice, trying to repair.
Had no issues repairing my two AHM Alco Century GP 24's so at this point I am 2 out of 4 in loco repairs.
Hoping to be 6 out of 8 when I am done with the Marx and three AHM GP-18's.


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## mopac (Feb 24, 2011)

NAJ , I have been thinking about your engine today while I was at the casino.
Of coarse I lost. Lets backup a bit. Motor ran when you touched one wire from
transformer to B or C. And the other wire from transformer touched to the other
motor terminal. Am I correct? Ok, that's what you need to end up with. One truck
to terminal and the other truck to the other terminal and it will run. B and C are
not connected. Inside the motor or not. It will not work if they are connected.
The bottom terminal is soldered to the motor case. And the motor case is soldered
to the plate that holds the truck under the motor. Am I right? Ok, that is one side of the power. You need to run a wire from front truck to the upper motor terminal That would
be the other side of power. It looks like there is a small tab next to the terminal. That is where the wire from front truck needs to be soldered. Unsolder or cut that wire that
is currently running from front truck to the motor housing. It is for the light and I think
you should get engine running and then worry about the light. The way it is, the motor 
will be shorting out and will not run. This should not be this difficult. One truck to a
motor terminal and other truck to the other terminal and it will run.

If you have a multi meter make sure you have continuity from rear metal wheels to the motor housing.
Then check for continuity from front metal wheels to where you are going to solder the wire that will run
to the upper motor terminal. I am sure it will run then.

That wire that looks like a spring on each plastic nub next to the metal terminals is holding the motor brushes in place. don't mess with them. Even though I have never worked on a Marx, they all work the same.


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## NAJ (Feb 19, 2016)

mopac said:


> Motor ran when you touched one wire from transformer to B or C. And the other wire from transformer touched to the other motor terminal. Am I correct? Ok, that's what you need to end up with. One truck
> to terminal and the other truck to the other terminal and it will run. B and C are not connected. Inside the motor or not. It will not work if they are connected.
> The bottom terminal is soldered to the motor case. And the motor case is soldered
> to the plate that holds the truck under the motor. Am I right? Ok, that is one side of the power. You need to run a wire from front truck to the upper motor terminal That would
> ...





NAJ said:


> I am now verifying every metal mating surface where current has to flow is clean/tight with good continuity (0 ohms resistance), from all wheels to the wheel chassis's to the motor and ballast housings to the motor and all points in between and that the motor housing is secured to the truck so it will not move.
> 
> Verifying good electrical connections is the reason I am curious how current flows to the motor on this setup.


I have already been testing electrical continuity.
There was a separate wire for the lamp which is no longer there.
Once I have both Truck Assemblies back together and verify continuity from the wheels to the metal housings on each truck (front truck is completed) then I will apply power to the motor terminals to be sure it spins the wheels freely without binding.
Once that is verified I will place both trucks and the driveshaft back in the lower frame and try it on the test track and use jumper wires to electrically connect the front truck to the motor to see what is needed to make it operate properly.
Once that is determined then I will solder a permanent wire in place.

Probably will not be to that point until sometime next week.


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## mopac (Feb 24, 2011)

Sounds like a plan. Good luck. Let us know.


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## NAJ (Feb 19, 2016)

mopac said:


> Sounds like a plan. Good luck. Let us know.


Certainly will and Thanks everyone for your interest in this project.


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## NAJ (Feb 19, 2016)

The tabs on my wheel chassis are broken and to this point I have not come up with a suitable way to secure it.

There is a chassis/truck available on eBay that would help me immensely getting this loco running again however the pic in the listing is very blurry and I cannot tell if the tabs that secure the metal chassis to the plastic truck are intact.

When this is put together properly the tabs protrude through and are bent over to secure the wheel chassis to the truck.

I sent a message to seller asking but no response to this point.
Can anybody tell by the pic if they can see them?
The second pic shows the top where the tabs would be seen.

http://www.ebay.com/itm/191994009826?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT


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## NAJ (Feb 19, 2016)

Won a Marx F-Series Loco (listing states moves in both directions) on eBay for under $10.00 shipped so I should be able to create a Great Running Marx F-Series Loco between the two of them.

Probably will not be here until next week so I will not see it until the following weekend
(I have all packages delivered to my Son's house because my post office cannot read) so sometime right after Thanksgiving...
Keep your fingers crossed.


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## NAJ (Feb 19, 2016)

Time toput this thread to rest.

I failed, was not able to get the loco running.

The motor operated fine with no load but as soon as it had to mesh with the worm gear that turned the wheels it stopped.
It did not have the power to turn it even though I could move those gears with just a little touch of my finger.

I was able to get another for parts online but the motor was different and had issues, the plastic housing was broken where the brush arms attached.
I attempted to fix it to no avail so I am done, time to move on.

The Marx loco is now relegated to "dummy" duty and just looking pretty on the layout.
Since it belongs to one of my Grandson's and he only plays with his trains 3-4 times a year all is good (stored under his bed).
Last year I got him a Lifelike NW GP-38 that runs as smooth and quiet as can be (wish my AHM's ran that well) so he is fine with that.


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## mopac (Feb 24, 2011)

Sorry to hear. You certainly tried. It happens. Dummy idea sounds fine. Thanks for letting us know.


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