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Locomotive not running

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  • Member since
    June 2024
  • From: Oakland, California
  • 12 posts
Locomotive not running
Posted by TrainGuy4014 on Friday, July 12, 2024 8:59 PM

I had just bought and fixed a Lionel postwar nw2 switcher, but when I put it on the track, the e-unit buzzed, but nothing else happened.

Tags: Broken , NW-2 , O-Gauge , postwar
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    June 2013
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Posted by smokey1 on Saturday, July 13, 2024 7:13 AM

I'm wondering 2 things, do the wheels turn easy by hand? and could you of accidently ( I know I have in the past. ) wired it up to the motor from the E-unit. If you have another postwar engine that is running fine, and follow the wires from the E-Unit to the motor one by one, not just look but run your fingerrs touching the wires the whole way. You may also have a cold joint, where it looks soldered but actually isn't. 

  • Member since
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  • From: Oakland, California
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Posted by TrainGuy4014 on Saturday, July 13, 2024 8:39 AM

The wheels feel kind of locked up p, but only compared to a scout engine. this scout engine is my only other locomotive. It runs great but I cant exactly follow the wires, as it is enclosed.

  • Member since
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  • From: Henrico, VA
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Posted by Flintlock76 on Saturday, July 13, 2024 9:56 AM

TrainGuy4014

I had just bought and fixed a Lionel postwar nw2 switcher, but when I put it on the track, the e-unit buzzed, but nothing else happened.

 

Without having the engine in front of us it's going to be hard to diagnose what the problem might be, we'll have to guess.  But since my guesses are as good as anyone elses, here goes...

The problem might be with the e-unit itself.  Have you tried manipulating the e-unit  lever to bypass the unit itself and send current directly to the motor?  E-units can go bad in various ways, I had one fail when one of  the rotor points broke, the unit buzzed but the rotor wouldn't turn to complete the cycle.  Or one or more of the fingers that contact the rotor can be broken, or the e-unit itself can just be dirty and loaded with dust and gunk.  Sometimes a spray with electrical contact cleaner is enough to take care of the problem.

Since it's a Post-War can you turn the drive wheels by hand to be sure they're not locked up?  It won't be as easy on a diesel switcher as a steam engine but it can be done.   

Pull the shell off the switcher and visually inspect the wiring from the e-unit to the motor, make sure nothing's come loose.  It shouldn't be hard to do. 

Aside from that I don't know what else to suggest.  At any rate look for the simple thing first, the fix might be easier than you think.

Good luck!

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Posted by El Fixes Things on Saturday, July 13, 2024 3:56 PM

Wayne and Smokey have already provided some good thoughts and advice, but I'll chime in too.

I think it would be helpful to know exactly which NW-2 you have, and perhaps a link to a video of what it's doing.

Earlier switchers made from ~1949 through ~1955 had a diecast chassis and trucks. These were generally the same as those designed for the early ALCo FAs like the 2023 Union Pacific and 2032 Erie. These models use a well regarded motor that could be unscrewed from the truck via a screw on the bottom of the powered truck. The E-Unit  cutout lever projected down underneath the chassis. 

Starting around 1955 a cheaper version of the NW-2 began appearing that had a sheet metal frame and trucks made out of sheet metal with diecast truck sideframes. The motor was no longer a seperate, removable unit, but rather integral to the powered truck. The E-Unit cutout lever on these models also projects underneath the chassis.

In the waning years of the postwar era, the design changed again, now using the plastic truck frames that were also used by 200 series ALCo diesels. On these models, the E-Unit lever typically sticks up through the hood, rather than down under the chassis.

When MPC took over Lionel, the design was at least initially cheapened further- whereas postwar models had pickup rollers on the un-powered truck, on MPC models the collector moved to the powered truck, using the same rollers as 'General' steam locomotives and plastic 'Scout' motors, where the roller is a metal ring that fits into a plastic bottom plate, rolling around a pivot that is molded into said plate. At least on the early MPC model I have, the motor no longer has proper 'oilite' bearings for the motor armature, instead having integral plastic ones.

The earlier two styles appear to have always come with 3-position E-Units, however the latest postwar versions and early MPC units would have either a 2-position E-unit or a manual reverse lever. 

Please feel free to correct me if any of this information is innacurate, this is just my general knowledge/understanding from looking at pictures of models, flipping through my Greenberg Guide, and visiting the 'tandem-associates' page, which afaik is more-or-less a digital version of an older Greenberg book. These resources are far from infaliable.

The general point though is there were many different versions of the NW-2's internals, and because of this, some likely issues are universal (a bad solder joint/broken wire, for example) and some are unique to different versions (for example, the later, integral truck/motor can develop an issue where the armature strikes the field within the motor due to a combination of bearing wear and slop or misalignment between pieces of the motor truck assembly).

An E-unit working, but no movement or motor noise, is most often caused in my experience by a disconnected/broken wire between the E-Unit and the motor. It can also be caused by an E-Unit that is dirty or has mangled contact fingers.

-Ellie

PS: these locomotives all have a worm drive, whereas most of Lionel's steam locomotives have spur gear drives. The diesel locomotives should normally be much harder to manually turn the wheels on, but it is often possible to turn them by hand with some effort. Being unable to turn the wheels by hand may or may not mean the wheels are jammed, but it's worth checking the gears for anything that may have gotten lodged into them.

  • Member since
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  • From: Oakland, California
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Posted by TrainGuy4014 on Saturday, July 13, 2024 7:24 PM

I got it running! I put the transformer on full power, and saw the wheels moving slightly. They were speeding up, and very quickly, it was running at full power!

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Posted by El Fixes Things on Saturday, July 13, 2024 8:04 PM

That's great to hear! Always nice when it turns out the problem was something simple.
I wonder if maybe some dried up lubricant was gumming up the gears and making it hard for the locomotive to start up. You might want to give it some fresh lubricant if you haven't already.

-Ellie

  • Member since
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  • From: Henrico, VA
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Posted by Flintlock76 on Monday, July 15, 2024 8:19 AM

Outstanding!  And take Ellie's advice, put some fresh lube in there!  Old gunked-up lubricants cause a lot of problems in these old engines.  Post-war era lubricants got the job done but weren't as good as what we've got now.

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