# Lionel KW transformer



## c6vette (Sep 18, 2012)

I just picked up a KW transformer but no user manual. One question, the red light on the unit, is that an overload light or a light to indicate the unit is on? Any help would be appreciated.
Al


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## gunrunnerjohn (Nov 10, 2010)

The red light is an overload light, so it's a good thing it's not on! 

I suggest checking the rollers before using it, if they're worn down to the arms, moving the controls will score the windings and quickly ruin the transformer. They're one of the most common maintenance items. The other thing I'd look closely at it the power cord, they frequently need to be replaced because the old cord is brittle.


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## c6vette (Sep 18, 2012)

gunrunnerjohn said:


> The red light is an overload light, so it's a good thing it's not on!
> 
> I suggest checking the rollers before using it, if they're worn down to the arms, moving the controls will score the windings and quickly ruin the transformer. They're one of the most common maintenance items. The other thing I'd look closely at it the power cord, they frequently need to be replaced because the old cord is brittle.


Thanks for the quick reply. You were right on re: the power cord. Cord is in good shape but had to change the plug just a few minutes ago. No AC was getting to the TF.

Not sure what rollers are. I assume I can get to them when I pull the cover off( done that already, no problem) Are the rollers replaceable? If so where can I get them.


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## Hellgate (Nov 9, 2011)

The rollers are replaceable although they might be riveted in. Either you can rivet them in place or just crimp the end of the rod so it doesn't pull through. You can get them at your local hobby shop or just type in "Lionel KW rollers" on Ebay. Hopefully your hobby shop will sell them to you at a reasonable price.


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## gunrunnerjohn (Nov 10, 2010)

I get my rollers from The Train Tender, Jeff has very reasonable prices and quick delivery. 

The way to replace them is to crush the old ones with a pair of needle nose pliers, then cut the rivet in the center with a Dremel cut-off wheel.

Make sure you don't try to bend the holder on the end of the arm, they are tempered and will break. I replace the rollers right in the transformer. It's a bit tight, but a lot easier than doing a major disassemble. For the new rivets, I just crush the hollow end to hold them in place.


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## c6vette (Sep 18, 2012)

Want to thank all for your help. Learned a lot in a short time. My rollers were almost gone, but no damage to the coil yet. Will replace. The forum members saved me a future costly repair.


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## gunrunnerjohn (Nov 10, 2010)

Whenever someone mentions a new (old) PW transformer, that's one of the things on the checklist.  Another problem spot, also easily fixed, is the binding posts. Sometimes the cheap crimps give out, you can also get replacement posts from the same source as above, and they are easy to install. Just used up my last bunch on a new (old) ZW, so I'm due to make an order.


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## trainguru (Jun 28, 2011)

Shouldn't this be in "O-Scale"?


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## gunrunnerjohn (Nov 10, 2010)

Yep, I moved it to O-scale.


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## old464 (Oct 12, 2011)

he should change out the breaker also to a modern type. heck take it to a hobby shop for an overhaul. cord, breakers rollers, etc. 
chris


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## servoguy (Jul 10, 2010)

I recommend soldering the rivets in place rather than crimping them. This will make a better electrical connection than crimping. It is also easier, quicker and doesn't require any special tools. Make sure the roller is free t move before you solder the rivet in place.


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## gunrunnerjohn (Nov 10, 2010)

I crimp them and then solder as well. The crimp keeps them in place before the soldering. After taking the old roller out and removing the old pin, use something like Scotchbrite to clean up the copper arm end nice and shiny so it'll take the solder easily. Many times they're pretty dark, and you might have difficulty soldering if you don't clean them first.


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## BigAl56 (Dec 14, 2011)

I use a small punch tool. I lay their roller arm down on my vice and gently tap the open end of the rivet with a punch. A couple of taps closes the end and will prevent the rivet from coming loose. You want to make sure you to not make the roller connection too tight as you want the roller to roll gently across the transformer.

Rollers and rivets are a very common eBay item. Just type 'KW Roller' into the eBay search box.


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## gunrunnerjohn (Nov 10, 2010)

I don't take the roller arms out of the KW or ZW to replace the rivets, speeds the job considerably.


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## billshoff (Nov 4, 2011)

Any one have pictures showing how to do these repairs? I don't know what a roller looks like!


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## servoguy (Jul 10, 2010)

If you have a KW, ZW, Type V or Type Z, just open it up and look.


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