# 2085D Mallet Dual Motor Issue



## [email protected] (Dec 31, 2012)

Hello all! This is my first post so be nice.  I've recently acquired an LGB 2085D from the late 80s/early 90s. It is all original and is running on an analog track with a 1 amp transformer. The front motor was bad on arrival. The loco ran for a few minutes, then shuttered, then a "buzz" was heard from the engine. The loco would move a bit again when the voltage was reduced but then stop completely. I took the front motor out and gave it a bench test by applying transformer leads directly to the terminals. It was choking to say the least.







I did order a new short shaft motor, but the questions remain:

1) Will I need to replace the other motor as well? The rear motor seems to run strong with the same bench test. I had it going for many minutes without a single issue.

2) What would happen if I were to test the loco on the track running only a single motor?

3) Should I choose to not replace the rear motor, and, unbeknownst to me that motor were to fail while the new motor was installed, will the new motor or interior components be damaged?

4) If I were to upgrade to digital, and I wanted to replace the circuitry, do I understand correctly that I can now replace the analog circuitry with a single motor/sound decoder board (Massoth, Zimo etc) and not require more than that?

5) Is a 1 amp transformer enough to run a loco of this size with three DB passenger cars with LGB "3030" lighting in tow? 

6) What kind of technology is built into the locomotives in regards to overheating or a tired motor? I mean the motors seem strong, but under heavy load they must get really hot!

THANK YOU in advance for your help!
Calvin


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## TheRoundHouseRnR (Jul 15, 2012)

Hello and welcome,

1) the likely hood of the old motor running in sink with the new motor is slim . In fact all motors don't run identical. However they need to be close . If one is a little bit slower than the other, thats ok. But lets say the new motor starts off at around 2 volts and the other around 5 , it will put unwanted strain on both motors and gear sets. So look out for that when you reassemble. 
Also , well known problem with these engines is the smoke fluid leaks down the stack right onto the front gearbox and fouls the brushes in the motor. So make sure this is not your problem. Try cleaning out the motor with electrical spray, and clean the commutator with 3000 grit sand paper.I have brought a lot of these motors back to life this way.

2) The loco will run with a single motor but will put unwanted stress on side rods. The front and rear wheels of each gearbox keep aligned by gearing and the middle wheel set is guided by the side rods. If you where to run with motor removed ,theres nothing to keep everything in quarter as the motor would keep front and rear wheels quartered perfectly through gearing.

3) Again refer to answer 1, if they run close they will be fine. If it fails do to common wear you will notice it well before any damage would be done. The loco would simply not run anymore. No damage to new motor or interior circuitry will be done if caught early.

4) Yes it can be updated to DCC but this older loco will need the track power isolated from the motor pickups. 

5) I'm afraid not. You should have at least 3 amps to run this loco at speed with lighted cars. The loco with smoke and both motors will draw around 1 amp to 1.5 depending on load in tow alone.

6) No internal breakers or anything like that. The motors basically see direct track power on this pacific engine. Some LGB engines ,the electronics are installed that make the motor start around 6 - 7 volts so the smoke and lights are going before the loco. So if motors are overheated or develop some type of issue and not caught in type, you see that wonderful blue smoke. I still wouldn't expect any damage due to how these circuits are designed. LGB builds thing pretty tough . The plastic being LURAN-S is designed for the desert heat and think how hot the motors get out there.
Good luck , anymore questions , let us know.

The Roundhouse RnR


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## [email protected] (Dec 31, 2012)

Well that was quite a response. Thank you! These answers will help me in my efforts to revitalize this loco and start this neat new hobby. This locomotive is simply stunning! I'm quite excited to see its full potential! 

One other question comes to mind: I have read a little here and there about different kinds of motors and their applicable housings. Are the original motors still considered strong, quality motors or is there a model that is suggested with better specifications? 

Thank you! And happy new year! 
Calvin


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## TheRoundHouseRnR (Jul 15, 2012)

Im not sure of your question to be honest... If you are asking is there a better motor to install in the loco , i would say not really. LGB used buehler motors in almost all their locos except their cheaper toy line stuff. Installing a different motor would never be worth the time and effort in my opinion. Buehler motors are reliable , strong motors. Most of the failure comes from over oiling/greasing and then it works its way into the brushes and fouls things up. Granted i do have some loco's where the brushes are worn down to the nub but they served there time ... beleive me. 

LGB did a test on a stainz loco in the factory. They left it run steady to see what breaks first basically. Sorta Rip, S***, or bust kinda thing. I wish others manufacturers would do this, or if they do , show there results. The distance it would have traveled was equivalent to driving from the east coast of the US to the west coast. I dont think you need to ask much more than that. 

If you can , try and find the older style motor with the black and red brush holders. They can be serviced easier and seem to hold up better. With the newer style enclosed can motors , i have noticed that the bearing near the brush side of the motor wears out and allows the shaft to run untrue. Also, there is no where for carbon brush dust to go and it ends up clogging the commutator which leads to higher amp draw, and eventual failure of the motor. Also, you can get new replacement brushes for the older motors. 

The Roundhouse RnR 

P.S. I have this same loco and i have worn out two front motors due to smoke fluid before i figured out what was going on. Thanks to a little tip from others that have been ,there done that. I have since sealed up the problem and have had no issues since.


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## Dan Pierce (Jan 2, 2008)

I took the 2085 and added the pulsed smoke from Train-Li, the Zimo 6 amp decoder (MX695) and the rear coupler is now tied to a servo. 
It is now an awesome engine. 

Note that the LGB motor under load can draw an amp, plus lights and smoke add more current and lit passenger cars even more!! My minimum is 8 amps for dc or DCC operations on my RR.


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## [email protected] (Dec 31, 2012)

Sorry for not being totally clear.







But yes, you nailed it. I was wondering if I should put in a more modern motor. The motor I ordered was a direct replacement with the red and black bushings. And wonderful advice with sealing the front motor! I'll have to take a closer look at it and do just that!

Thank you!
Calvin


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## chuck n (Jan 2, 2008)

Welcome! While you are in the motor blocks check the idler gears, they are the gears that engage the worm gear on the motor. The teeth should be straight across and not cupped. If they are cupped replace them. I got mine from TRAIN-LI. They are a sponser here on MLS. Click on their logo for their phone number. Chuck


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## TheRoundHouseRnR (Jul 15, 2012)

I actually didn't seal the front motor. I just used a very sparing amount of a high temp silcone around the smoke unit from the inside, in case i every had to replace the smoke unit. Sorry about the confusion. The Roundhouse RnR


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## TheRoundHouseRnR (Jul 15, 2012)

Heres a neat little vid, something along the line of what Dans talking about. lgb 2085d - youtube video-


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## mbendebba (Jan 22, 2011)

I have not noticed much of a difference between the life span of old vs new style buhler motors, and I have handle many of both over the last couple of years. 
As RoundHouse says the old style motor are easier to service, but I do not beleive that replacement brushes are easily available. 
Finally, the new style motors appear to more efficient at low voltage, the do require as much voltage to start moving especially in DCC operations. 

Mohammed


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## TheRoundHouseRnR (Jul 15, 2012)

Mohammed ,The brushes can be found at champex-linden. I have also seen them on ebay from time to time. I never said they are easily available but they are out there. There is nothing for the new style motors. Also ,i have about 10 newer style motors where the bushings near the brush side of the motor egged out and the shaft wobbles so bad the armature of the motor hits the magnets. I have never seen the older style motors do this. This is after lots of abuse ofcoarse. 

One good application of the newer style motor would be in the track cleaning engine. The cleaning motor spits cleaning pad dust all over the place in that loco. The newer enclosed motors should provide some protection from that. 

Interesting thoughts of the newer style motor being more efficient. Both old and new motors are of the same design, as far as, poles, resistance, and armature. As far as DCC, starting voltages can be changed and set for all kinds of motors. As i said earlier , no two motors run the same. So i dont see an advantage there. Infact in analog , the older motors starting at higher voltage could be an advantage. 

To some it up , both are great motors and very similar. I have many of the newer style replacement motors and older ones to. I am more talking about long term service. Call me wierd but if i have an older german lgb loco , i like to have the orginal motors in them. However, i would never turn my nose up at a newer motor if i couldnt find an original. I like to run trains to much lol. 

Good luck, hope your motor comes soon. The Roundhouse RnR


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## mbendebba (Jan 22, 2011)

RRoundhouse: You are absolutely right about everything you said. I do have an adequate supply of brushes for the old style motors and I do not hesitate to put them to use in order to preserve for as long as I can the old style LGB Motors I have in my old LGB Lcomotives. 

Take care. 

Mohammed


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## [email protected] (Dec 31, 2012)

I will definitely take a look at the gearing to make sure everything appears straight and true. Very good advice! 

I'm also interested to see if anyone has the exact manual for the 2085D in PDF. It seems I can find manuals for quite a few other Mallets but the 2085D is evading me. I've checked three databases that have been identified here in the forums. If anyone has one, would you mind forwarding it to me (email is my forum name) or provide a link? Thank you!


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## [email protected] (Dec 31, 2012)

Hey that YouTube link shows my Buddy Alexander's train in Germany. That's ironic!


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## [email protected] (Dec 31, 2012)

I have the documentation I needed. Thank you everyone!


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## bobpcrcd (Oct 2, 2008)

I am looking for a set of four (4) side rods (or Main Rods connecting the drivers) for an LGB 2085d locomotive. I am trying to repair a locomotive for the Presbyterian Hospital Pediatric Unit in Charlotte, NC. Any help you could provide in locating and purchasing these parts would be appreciated.

Bob Ferguson
Garden Railroad Supply Company
Martinez, CA


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## BigRedOne (Dec 13, 2012)

Bob,

I'd start a new thread for the topic, with a specific title describing your question.

Often old threads don't get viewed a lot, and people will decide to view based on the title.


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