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I have this Lionel ZW 250-watt transformer that was experiencing some connectivity across channels A and D.  When either throttle was rotated, BOTH channels A and D would show the voltage.  Upon examination, channel A had a loose contact on the contact late assembly and the transformer was missing both tube insulation pieces.  Not sure if that was related to the problem in any way but this process should find and correct the problem.

So, I decided to tear the transformer down, clean it, and rebuild from the ground up.  I thought perhaps that those who have never seen the breakdown and reassembly of the ZW might be interested in the process.  If not, there are plenty of other posts to read !

The rebuild will include a new cord, rollers, binding posts, 16 amp whistle diode of the stud variety, TVS installation, a quick acting 15 amp resettable fuse breaker, and new wiring where necessary.  The necessary repairs will be made along the way and it will be deep-cleaned as it is reassembled.  Should last another 70 years!

In the initial examination, I had some concerns about the possibility of asbestos being present in the old cloth wire coverings.  I had the transformer tested at a local environmental service facility.  They tested 5 different wires and found no asbestos in the coverings - a relief to me!

The pictures below show the initial examination and the disassembly of the transformer as well as the cleaned casing and handles.  I will keep you posted on the progress.

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Labeling the wires helps with reassembly !

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Goo-Gone to remove sticker residue.

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The handle on the left had a spin on the buffing wheel - quite a difference!

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A "before-and-after" shot of the case and handles.  I did my best on the "duct-tape" residue on the case.  I am hoping the shine will distract anyone from seeing it !

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Stay tuned!

Dennis

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Original Post

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Dennis,

Perfect timing!  I just got a box of postwar trains from friends of ours, who were downsizing.  In the box was set 2171W and a ZW. The ZW is the early 275 watt version with small name plate on top.  I quickly popped the top off and one of the rollers is practically gone.  I plan to do a complete service of the unit same as you.  I just ordered a ZW repair kit which includes rollers, new 15 amp breaker, stud diodes, and power cord.  Good luck on the rebuild.

Joe

@Joe Fermani posted:

Dennis,

Perfect timing!  I just got a box of postwar trains from friends of ours, who were downsizing.  In the box was set 2171W and a ZW. The ZW is the early 275 watt version with small name plate on top.  I quickly popped the top off and one of the rollers is practically gone.  I plan to do a complete service of the unit same as you.  I just ordered a ZW repair kit which includes rollers, new 15 amp breaker, stud diodes, and power cord.  Good luck on the rebuild.

Joe

Joe: What is this ZW Repair kit you referred to and where did you purchase it? I have two ZW’s one a 275 and a 250 both showing and acting their age.

A couple of steps today.

I decided to have another go at the cover and that residue.  I used a heavier grit polish and was able to remove most of it and I think it looks better.  20220801_195747

I also cleaned a few of the parts for the left handle with a vinegar and water solution.  Here's a before and after shot.

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Last edited by dennish

A little progress with the handle components:

But first, to give credit where credit is due, I am following to rebuild job that I found on YouTube by a fellow who goes by TheCreativeMind.  He shows the process that I am completing and my steps mimic much of what he did.

First, I have to label wires lest I forget what goes where !

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I got a little ahead of myself with the stud diode.  That will come out and go back in during the rebuild.

A 'before cleaning' and 'after cleaning' picture of the components:

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Thanks for the comments and for checking in!

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I did a complete rebuild of my two zw’s last winter. Noticed you drilled out the center rivet of the whistle/direction assembly. I did the same but used a machined part from PE Design and Manufacturing instead of retaping the old rivet. It is called a "ZW-74 Switch Rivet" sold as a pair. I picked them up at York, but they can be bought on line. I think it was around $20.00, but since I didn’t have the tools to re-tap the original, it made sense for me.

Also picked up a “Universal Mini Press” to crimp the roller pins. This is not a cheap solution, but it made the rebuild easier with very good results.

Robert,

I have a pair of rivets for the whistle/direction assembly.  Not sure if I am going to use them or drill-and-tap.  I do not want that screw to loosen over time.  I cam press the rivet on with the arbor press.  I have a pair of parallel jaw pliers that work well for pressing roller pins.

I had to "repress" a couple of the soldering lugs on the whistle/direction assembly.  One had completely broken loose (I believe it was channel A, one of the offending channels in the first place).  A couple others simply spun around but had not become disconnected.  The Hobby Horse press sure made that job doable!

Did you replace the resistor wire and 6-volt lamp with an 18-volt bulb?  If so, what wire gauge did you replace the resistor wire with?

Dennis

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Last edited by dennish

Some parts arrived today and I made some progress on reassembly.  There were 3 parts in the rebuild that were completely missing from this transformer: the tube insulation (ZW-81) on each side, a bushing (ZW-157) on each handle spindle and a spacer (ZW-166) between the contact plate and contact springs on each side.  Maybe they made them without those parts back in the late 40's and they are part of the reissue of the 275 watt ZW.

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We're getting closer!!!

Dennis

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CleanedContactDirtyContact

Hi Dennis,

When you serviced the whistle/direction control, did you put any conductive grease where the contacts slide?  I am rebuilding my ZW and I am up to taking that apart to clean and service the contacts.  I saw one video where a guy put a dab of grease on all the contacts.

Also learned that a simple solution of lemon juice and table salt are a great cleaner for the metals parts.  It has completely restore the arms for the rollers to shiny condition.  Looks brand new!

Joe

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Last edited by Joe Fermani

I am happy to report that the 250 watt ZW is back together and functioning well!  Whistles like a champ!  The only thing I am not happy with is the 15 amp resettable circuit protection.  It does not trip and reset as quickly as I hoped.  In fact, it is very difficult to trip period!  I am thinking of using a 5 amp resettable circuit breaker similar to the ones we use between the exterior of the transformer and the track.

It has been a journey that I look forward to repeating again.  Our club has twelve ZW's that need cleaning, refurbishing, etc.

Joe, I am sorry I did not see your post.  I did not put any conductive grease on the contacts.  I just scrub them with vinegar and salt and polished them with some ultra fine sandpaper.

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