Vintage Jeep Ignition Switch - Part 2: Rebuilding An Original Switch

[snoopy2x]

Part 2: Rebuilding An Original Ignition Switch 

The first thread in this series, Vintage Jeep Ignition Switch - Part 1: Refreshing An Original Switch , covered the internal cleaning of an original switch without disassembling it.  That process may suffice in some cases to restore an older switch to good working order.  In the case of the original 50-year old ignition switch from my 1967 CJ5, however, it proved to be insufficient to fully fix the problem.  This thread picks up where I left off in Part 1.

When Moses and I initially discussed this idea in an off-forum conversation (much of which is excerpted in When to Restore a Vintage Jeep Ignition Switch), he and I both expressed some apprehension about the wisdom and viability of de-crimping and then re-crimping a 50-year-old diecast metal switch housing in order to repair or replace the switch's internal parts.  My original inclination to get the switch working was to try to clean it without taking it apart, as discussed in Part 1.  However, when that process failed to fully fix the intermittent connectivity issue on the Accessory terminal, rebuilding it seemed the only option left to try if I wanted to continue to use it (which I do, particularly since I still have one of its original Jeep logo keys).  

The OEM ignition switch for my CJ5 (Kaiser Jeep part # 924918), which was manufactured by Pollak, is unfortunately no longer available.  As far as I've been able to discover, there were no crossover uses of that particular switch with any other vehicles.  

However, in researching this subject on the internet, I realized that certain other similar ignition switches made by Pollak (or Aetna-Pollak, as it was called in the late '50's and early '60's) during the same general time frame might very well share their internal parts with my original switch.  If so, having an NOS example of one of those switches would allow me to cannibalize its parts to repair mine - assuming that I could successfully disassemble and then reassemble mine without ruining the diecast housing.  

The switch that seemed to be the closest visual match to my Jeep's original ignition switch was a 1956-63 Rambler / Nash switch (AMC part # 3158414) made by Aetna-Pollak.  It was almost certainly produced a few years before the Pollak switch in my jeep was manufactured, and had a much shorter lock cylinder socket.  However, the "business end" of the switch containing the internal parts appeared to be outwardly identical to that of my CJ5's OEM switch.  

NOS Rambler / Nash ignition Switch (L) and OEM Jeep CJ5 Ignition Switch (R):

 

To test this theory, I bought an NOS Aetna-Pollak manufactured Rambler / Nash 3158414 ignition switch on eBay.  Also listed were several 3158414 replacement switches made by another manufacturer (Sorensen, whose products were carried under several different brand names), but the OEM Aetna-Pollak version I was looking for was likewise available.  

Here's a photo of a nice NOS example of this switch:

 

When the NOS switch I ordered arrived, it became clear that my original ignition switch was indeed nearly identical to the Rambler / Nash switch, with the exception of the length of the lock cylinder socket and the configuration of the 1" threaded portion that extends through the dashboard.  The two switches shared the same base, and it seemed very probable that their internal operating parts would likewise match.

 

As can be seen above, the thermoplastic / bakelite base is secured into the diecast housing by six crimps around its circumference.  I decided it would be a good idea to disassemble the "donor" switch first before trying to take my original switch apart, as this would give me some practice with de-crimping an older diecast metal switch housing.

I set about taking the NOS Rambler / Nash switch apart by first placing its lock cylinder socket in a vise with "soft jaws" type inserts.  Note: I would highly recommend these polyurethane vise inserts to anyone planning to rebuild a similar ignition switch, as I found them to be an indispensable tool in this project:

https://smile.amazon.com/gp/product/B00004XPVT/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

To de-crimp the housing from the base, I used used a small 1/8" flat screwdriver, gently twisting it back and forth between the crimps and the plastic base, to very gradually and slowly work each crimp outward.  

 

I turned the switch housing as I worked. Soon, there was enough space between the metal and the plastic base to move up to a 1/4" flat screwdriver.  It took about 15 or 20 minutes of patient, careful work to bend all six crimps far enough outward to remove the plastic base from the housing.  

Once it was apart, it was easy to see how the switch operates.  It's extremely simple, and in fact, there is only one moving assembly inside it.  This assembly includes a plastic core keyed to a copper alloy disc with a coil spring in between them that presses the disc into the terminal contacts in the base.  The assembly turns with the lock cylinder to make the proper connections to the stud terminals on the base at each different ignition key position.  Also, the copper disc has a starter tab that contacts another tab on the base when the key is turned to the start position, causing that circuit to close (and the starter motor to engage).

The NOS switch with the base removed, showing the copper alloy disc:

 The rotating assembly (center) lifted out and turned over:

 

By this time I was both practiced and "on a roll" - so I moved on to disassembling my original switch using the same technique, doing as little damage to the metal as I could as the crimps were worked outwards.  It's not difficult to take these switches apart, though it's a bit painstaking to do so while keeping the diecast housing in re-usable condition at the same time. 

Once it was apart, two things immediately became apparent.  First, the internal parts were definitely a good match for those in the NOS Rambler switch.  Second, the reason my original switch had been having a connectivity problem was clear.  Even after its cleaning with Deoxit (see Part 1 of this series), the rotating copper disc showed evidence of burning in several areas. Also, the starter tabs on both the disc and the base were significantly burned:  

 

 

The only noticeable difference between the old internal switch parts and the NOS parts was that there were two copper tabs on either side of the NOS copper disc that snapped into tapered grooves in the edges of the plastic core.  These tabs keep the coil spring slightly compressed and the rotating assembly parts from separating.  The slightly later OEM Jeep switch did not have these two tabs for some reason, but having them on the NOS part made reassembly easier.

 

I cleaned the original housing with denatured alcohol to remove the remaining original grease that the Deoxit hadn't dissolved, and cleaned the NOS parts removed from the Rambler / Nash switch the same way.  After letting the alcohol evaporate, I coated the NOS copper alloy disc and the terminal contacts in the base with Deoxit Shield, which is designed to protect and lubricate clean electrical contacts in potentially harsh environments.  I let this dry completely before continuing with the reassembly.

 

At Moses' suggestion, I contacted Pollak, which is still in business, to ask what type of grease they use in their current switches (which incidentally are remarkably similar to the ones they made 50+ years ago).  Their rep indicated that they now use a grease called Rheolube 363.  Although Rheolube 363 is unavailable in the retail market, I was able to find its properties online.  After sharing that info with Moses, he recommended using a lithium-based grease he has found to be very effective, UltraLube LMX, for use in the rebuilt ignition switch.  Here's a link to that product (though it is available locally in many areas):   

https://smile.amazon.com/gp/product/B002BW1P6I/ref=ox_sc_sfl_title_3?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Using UltraLube LMX, I thoroughly greased the inside of the cleaned original housing, and then started reassembly of the switch.  

 

As the switch was being reassembled, I made sure to align the rotating assembly so that the semicircular hole near the center of the disc - into which semicircular tab at the end of the the lock cylinder fits - was correctly positioned toward the top of the switch (where the small groove is cut into the threaded end of the lock cylinder socket).  The photo below, looking down the lock cylinder socket, shows the proper positioning of the rotating assembly:

 

Additionally, the plastic base has a rectangular notch which must be aligned with a small tang on the metal housing.  The base also has six evenly spaced indentations around its edge, which correspond to the locations of the six crimps in the diecast metal housing.  The notch and the indentations in the plastic base, as well as the tang in the housing (the rectangular "bump" with grease on it), are visible in this photo:

 

After aligning the notch in the NOS base with the corresponding tang in the housing, the base could be installed.  It was a little tricky to get the new base fully seated, but using the vise (with only extremely light pressure) ensured that it was pressed all the way in: 

 

After lightly clamping the lock cylinder socket of the switch housing between the soft jaws of the vise, while continually pressing down on the base with my fingers, I used the edge/side of the end of a round steel punch, tapping it with a hammer very gently to gradually recreate the concave shapes of the original six crimps in the diecast housing:  

 

Tapping each re-crimp into the housing a little a time, I made multiple passes over each one, rather than trying to form any of them in a single pass.  Also, each time I moved to another crimp, rather than working in a circular motion to the next adjacent one, I went to the crimp 180 degrees across the base.  From there, I then rotated to the adjacent crimp, went to the one 180 degrees across the base from that point, and so on.  

I worked around the switch this way, making at least four complete rotations and turning the housing between the soft jaws of the vise as I went. This process ended up re-crimping the original metal housing around the NOS plastic base surprisingly well.  The base is very tightly secured, with no detectable movement between it and the housing.

 

Moses pointed out that if someone rebuilding a similar ignition switch was concerned about the possibility of moisture intrusion through the joint between the housing and the base, one way to mitigate this would be to fill the groove along that joint with a 2-part plastic epoxy.  He cautioned though that epoxy is not strong enough to substitute for crimps.  

The lock cylinder, having already been cleaned and lubed in Part 1 of this series, was reinstalled in the housing, using a small knife to depress the retainer clip and allow the cylinder to slide in:  

 

Turning the key through its positions, I checked the rebuilt switch for continuity, and am glad to report that it performs perfectly.  Testing for resistance, the ohmmeter registers much less than 0.5 ohms across each of the closed contacts, indicating good connections.   When the key is turned, it now "feels" like a brand new ignition switch.  

After shining up the housing, bezel nut, and terminal studs a bit, the rebuild was complete, and the switch was ready to be returned to service.  

OEM ignition switch as shown in the 1966 Universal Jeep Parts List, and the newly rebuilt OEM ignition switch:

[Moses Ludel]

Nice work, snoopy2x...Many will benefit from your patience and attention to detail.  The photos really help...Thanks!

Moses