I disassembled a couple of bent tab ignition switches for plating and then discovered there is more than one way to put them back together. There is an index hole in the switch body that should be on the bottom end of the switch when installed.



As others have already stated, the ignition lock cylinders offered by the suppliers need some re-work before they can be used. I put a small screwdriver in the key slot so I could turn the cylinder as I rotated on my belt sander. After reducing the diameter so that it fit, I filed one side of the tang so that it fits in the switch body correctly. The blue shaded area shows where metal needs to be removed.



I used #6 machine screws and nuts to snug everything up and check fits prior to re-riveting the assembly.






One other thing I noticed is that the lock cylinder does not fit into the original fiber piece without some re-work. The new switch kit parts have enough clearance to accommodate the difference.

A clearer drawing of where the tab needs to be narrowed.

I found that if you're installing a new back plate in a tab type housing it may need some fitting. The one I got from Lang's was excellent quality but its notches didn't quite line up with the tabs. This is because switches came from more than one supplier, and don't all have the tabs in exactly the same positions. The misfit was easily fixed by filing one of the notches a little wider.




A warped original back plate may not need to be replaced. Often it can be flattened by rubbing on coarse sandpaper.


Flattening a back plate may leave some of the dimples shallow enough that you will need to deepen them. You also want to bend the contacts up a little higher.

And the repro cylinders do not have the retainers that keep the tumblers from falling out when key is removed! That's a big issue if your lock does not have the tumbler retainer tabs shown in the 3rd photo from top (I had to add a sheetmetal band around the outside of the tube to retain the tumblers). Whoever (whomever?) makes these is so close yet so far from making the correct part. jb

Tom, the part you show in your first picture is the exact part I need to fix the "rebuilt" ignition switch that I got on Ebay. Right now, the lock tumbler spins 360 degrees when the key is inserted, the little "teeth" that limit the travel are broken or worn off.

Anybody have a good spare they would be willing to part with?

I've rebuilt several original pin type switch backs. I do like Steve mentioned, but use a finer grit sandpaper. I reset the pins with Crazy Glue, and clamp each one to the original thickness.

The original tumbler that was fitted to my bent tab switch does not have the retainers to keep the tumblers from falling out as shown in above photo. My guess is it has internal retainers built in to the housing. So not all the switches will have them, may boil down to who made the assembly.

I have a limited supply of the of the proper two rivets needed to re-assemble the switch body to the plate, if anyone is interested.

Steve I am interested. Please PM me with the details.
MarkG

Steve, any chance of the proper size of the rivets? I'm trying to reassemble a switch that was disassembled before I received it. Thanks, Dave

James, I put a repo cylinder in a switch this summer, did not have a tumbler retainer, made a sleeve from a piece of 1/2 inch diameter copper water pipe about 7/16" long. Also had to reduce the diameter of the replacement cylinder by about .020 of an inch. Why are there so many replacement parts made so close to being correct, yet requiring modifications before you can use?

Not understanding your question, Dave ?

Steve, was interested in the size of the rivets that hold the switch body to the plate. Since you had a limited supply, thought I could find them locally. Thanks, Dave

I'll measure & post a photo but they're not commercially available - these were machined by an old friend that's no longer with us.

Here's some rivet info - Mark & James - some are headed your way !

Since posting, I received a couple of PMs asking questions:

The lock cylinder does not have springs. The tumblers are these rectangular pieces. When the wrong key is inserted, one or more will stick up and prevent the cylinder from turning. When the key is removed, they fall away from the cylinder and also stop it from turning.



The replacement cylinders come with four tumblers and two keys. When you pull the key out all four tumblers are the same; two are located with the rectangles up, the other two are down. If they fall on the floor, they're easy to put back in order.

A couple of my ignition locks were broken when I got them and the key was difficult to insert. When I have an original key, I reuse the brass tumblers if they're still inside the switch and make use of the four that come with the new cylinder.



The cage in the cylinder varies. The ones with square windows will lose the tumblers. For these, I purchased telescoping tubing from McMaster and make a sleeve that has two tabs to retain the pieces. The tubing can be epoxied to the cylinder or green Loctite can be if it's a good fit.





The rivets sold by Langs are shown here:



And finally, one of my ammeters that's not at the plater. A Model A ammeter is shown on the left as reference.

In regards to inquiries regarding spares, I'm still in the process of putting three good switches together and don't know if I'll have any parts for sale. There have been numerous surprises as I open each one.

Ammeter - Model T on right



Telescoping tubing. I buy it in various sizes in one foot lengths.