# Lionel ZW 275 Transformer carbon rollers and cord replacement



## erkenbrand (Dec 6, 2010)

It was time to give my old ZW a refresher. I picked it up earlier this year, and it was fully functional, but it wasn't great. The cord, as usual, was dry rotted and falling apart. Also, the roller action didn't feel great. I also wasn't particularly happy with its overall look. I think it spent a long time gathering dust and dirt in an attic . . .










Here it is opened up:










I pulled the arms out, which requires pulling a pin from the inside and then slipping out the handle. This leaves the inner arm, spring and cup behind. Be careful. Those little pins have a tendency to disappear once you have them out. Actually pulling it is easy - just snag it with some needle nose.




























Once I had those apart I went deeper to free up the power cord. To begin there are four bolts on the base that need to come out:










Then, hold your hot soldering iron against each of these points while pulling on the power cord at each location. It should come apart pretty easily:










Now that it's part, it's time to get moving on with cleaning and reassembly.


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## erkenbrand (Dec 6, 2010)

To clean it, I gave it a bath in warm water and dish detergent. Yup, the decal lasted about 30 seconds, but I plan on replacing that once I place my next parts order.

Of course the only parts that actually got the bath were the top shell and control handles.

After I had it basically clean I went about polishing it. For this I used Wizard's One Step rubbing compound and polish. You can find this stuff at an auto paint supply store. I just applied it by hand with a soft cloth and then buffed it out. All of this helped a good bit.

I just wish I'd remembered to take an A / B photo.


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## erkenbrand (Dec 6, 2010)

Reassembly . . . I started with the power cord. First, I fed the new cord up through the hole in the base. I then knotted it a few inches down. This ensures that if somebody yanks on the power cord it won't pull the solder points.

Here's a photo of the knot in the original cord:










I then soldered the new leads into place:










With those done, it was time to replace the carbon rollers. 










To do that, I followed Gunrunnerjohn's advice and just crushed the old roller with my pliers.










Then, I used diagonal cutters to snip the rivet. Another option is to use a Dremel with a cut off wheel.

Replacing the roller was easy . . . just insert it and its new rivet. To set the new rivet I just squeeze it in some Channel Locks. 










Getting the arms back in is a pain. It's easiest to do it while the transformer is still unmounted. You can then reach in to set the springs and pins. Take note of the indexing of the power points on the aluminum plates.

After that, it's just a matter of bolting everything back down.


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## servoguy (Jul 10, 2010)

The secondary of the transformer looks like it has been too hot.


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## erkenbrand (Dec 6, 2010)

It does look that way, but it still seems to operate well. I don't know the history of this ZW, but I don't think it was treated gently.


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## servoguy (Jul 10, 2010)

I suggest you polish the area on the secondary winding where the rollers contact the winding. It looks pretty grotty. You can use a ScotchBrite pad or a wire wheel on a Dremel tool.


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## erkenbrand (Dec 6, 2010)

Thanks for the suggestion. I'll do that tonight.


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## tjcruiser (Jan 10, 2010)

Excellent stepwise service thread, with great pics! Thanks!!!

(Great reference for future tinkerers!)

TJ


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## gunrunnerjohn (Nov 10, 2010)

Note that it's much easier to replace the rollers if you don't remove the arms at all. I just spring them out about 3/4" from the transformer core and tie them in place. Then I do the replacement there.

The reason I recommend soldering the rivet is that on many of these you can see the results of heat on the arm end from a poor connection between the rivet and arm. The carbon roller naturally makes a better connection to the rivet as it rolls.


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## erkenbrand (Dec 6, 2010)

It is definitely much easier that way. I did the secondary rollers with it in the case. I already had the others out before I saw your post about just doing it all in place.


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## erkenbrand (Dec 6, 2010)

Completed the final work on the ZW today. I pulled the shell and cleaned up the windings with a scotch brite. Then, I cleaned off the label area with an alcohol wipe and stuck on the new decal. It's all ready for the future layout.


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## gunrunnerjohn (Nov 10, 2010)

Looks like a new transformer! :thumbsup:


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## tjcruiser (Jan 10, 2010)

Looks great.

Is that decal a sticky-peely type? Paper/film, or heavier printed aluminum?

Just curious,

TJ


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## erkenbrand (Dec 6, 2010)

It's heavy printed aluminum from Jeff. With a sticky back. It was $4.75 + the ride.


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## tjcruiser (Jan 10, 2010)

Thanks!


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## dindallas (Dec 12, 2016)

*Pictures Missing*

Does anyone have the pictures that were originally included in the first few posts on this thread?

Thanks


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## gunrunnerjohn (Nov 10, 2010)

No, they were hosted on an external site and obviously they were moved later. This is why we like people to upload graphics to the forum, they don't disappear later and render the threads useless.


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## Spence (Oct 15, 2015)

Whew; I thought I was the only one who couldn't see any photos.


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## gunrunnerjohn (Nov 10, 2010)

Well, these photos were hosted elsewhere and they're no longer there.


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## T-Man (May 16, 2008)

You tube has a bunch of rebuilds. Here is one explanation.


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## highvoltage (Apr 6, 2014)

This website does a very good job of explaining transformer rebuilds. Follow the links across the top for a specific transformer:

http://www.tranz4mr.com/Welcome.html


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