Wednesday, September 15, 2021

How To Replace the C3 Corvette Ignition Key Switch

Replacing a 1969 through 1982 C3 Corvette ignition key switch is a challenging task, but not impossible for the ambitious DIYer with the right tools and necessary patience to get the job done.

For this demonstration, I am using a standard 1969 steering column, but the removal and replacement of the ignition switch will be almost identical for most GM columns.

To gain access to the steering-column-mounted ignition key switch, a few things will have to come off. Based on whether your Corvette has a standard or a tilt/telescoping column, these will include the horn button, telescope lever, steering wheel, horn plate and brush, hub assembly, steering wheel lock plate, hazard light button, and the turn signal lever and switch.

Also worth mentioning is that you can replace the ignition key tumbler with the steering column in the car, so you do not have to remove it, which actually, makes this process easier.

However, if you also need to replace the sector gear, you may need to remove the ignition housing, something that will also require removing (or at least loosening) the turn signal switch.

To remove the steering wheel lock plate, you will need a special but fortunately inexpensive tool, and you will also need a steering wheel puller to remove the hub.

The photo above shows the lock plate removal and installation tool in action during the restoration of a 1978 T&T steering column I rebuilt for my '76 Vette. You need this special tool in order to safely remove the lock plate clip or ring. You can improvise one, of course, but for safety's sake just buy one. They are rather inexpensive ($10 to $15), and a good addition to your C3 Corvette/GM tool arsenal.

The 1969 Corvette column I used for this article had a bad ignition key tumbler, a chewed-up lock sector gear, and a bunch of missing parts. 

I was able to find an identical replacement sector gear for around six bucks including the lock rack (more on that later). Some of these components were used in many GM models, so do a little shopping around before overpaying.

I also ordered a new aftermarket ignition key switch from Amazon. The one that came with the column, although original and with the keys, did not work correctly. And again, you will have plenty of options when it comes to buying a replacement ignition switch.

By the way, if you want to have the correct GM keys, you can buy blanks at Corvette swap meets or online, and then have them cut to match aftermarket keys.

General Motors ignition (square) and door (round) keys have a code that identifies them, this way you know you are getting the right blanks. And they are really inexpensive as shown in the above picture I took during the NCRS swapmeet in Lakeland, Florida a few years ago.

Alternatively, you can buy key covers, both square and round. They are pretty cheap, look good, and sometimes you can find them in colors other than the original black if that's your thing.

If you are curious as to where to have your keys cut, there are many mobile locksmiths that can do the job. Also, hardware stores such as ACE Hardware have key cutting machines.


Rack and Sector Gear

As soon as I received the Dorman Steering Wheel Locking Rack and Sector Gear kit, I inspected the parts to ensure they would work. The brass gear rack in my 1969 steering column is in fine condition so I had no need to replace it. 

The sector gear, however, was chewed up to the point of being unusable, but the one in the kit was an identical match.

The rack, on the other hand, would have needed modifications to work in my steering column, but again, since mine is in good condition I did not have to resort to that.

The photo on the right shows the Dorman replacement part on the left and the original brass rack on the right. They are almost identical, but the aftermarket unit is wider so it would need modifications in order to work.

I am sure it fits other GM models, so if you need a replacement rack for your Vette, get the right one for your model year.

Having said that, the price of the Dorman kit was around $6 which is a bargain when you learn that "Corvette-only" sector gears retail for around $15 plus shipping in most cases. And that's just for the little plastic gear shown below.


Installing the sector gear

I have no idea if someone had taken the steering column apart at some point, so I hoped reassembly would be a reversal of taking it apart. I am sure there are tutorials available on how to install the rack, sector gear, steering wheel lock pin, and ignition key switch, but I decided to see if I would be able to figure the process by myself.

So I did a test-fit installation to take pictures, shoot a video (link at the end of the article), and see if my approach would work.

It did!

One caveat before I continue... this is how I did it. There may be better ways to get the job done but this is how I installed the aforementioned parts.

I started by snapping the rack spring into the assembly groove, followed by the rack and the lock pin.



The sector gear can be installed either by itself or with the ignition key switch. I inserted it by itself during the dry installation in order to engage it to the rack. But since the rack is under pressure because of the rack spring, you will have to compress it a bit for the sector gear to mesh properly.

The rack's teeth are approx. at a 45° angle that matches the sector gear since it enters the column's ignition housing at an angle. During the final assembly, I plan to grease everything generously for smooth operation.



The photo above shows the rack and sector gear in operation. When the ignition key is in the "Run" position, the lock pin is retracted thus allowing the lock plate and steering column to rotate freely.

When the ignition key is in the off or "Lock" position, the pin engages the lock plate and locks it in place, preventing steering wheel movement (photo below).


I also installed the ignition key tumbler to check alignment with the sector gear, and it meshed perfectly (photo below).


The ignition key tumbler has two tabs that slide into a channel in the housing, thus providing proper alignment. I took my time to ensure the tumbler slid easily into the sector gear in the "Locked" position, and this approach worked well.

In hindsight, the same can be achieved by installing the tumbler and sector gear as one unit. Just take your time so all the pieces are aligned properly.



Restoring the steering column

If you follow my blog, you know I restored a tilt/tele 1978 Corvette steering column for my '76, and I chose to install a newer model column for two reasons:

  1. The '78 steering column is 2"shorter
  2. I wanted to use a later-model C3 three-spoke steering wheel
However, this article is not about restoring a steering column, something I did regardless in order to be able to finish some of the repairs as well as this article. But if you want to see an in-depth restoration, click here for Part 1 of that Series.

To restore this one, I stripped all the thick layers of paint that accumulated over the years. The column looked horrible, and it took several coats of paint stripper to get down to the bare metal. Lots of scraping and sanding were also required.



But as you can see in the photos below, it was worth the effort. I spent a couple of hours getting all the components ready for primer.




Once all the parts were ready, I reassembled the ignition key housing. I thought about replacing the bearing even though it cleaned up nicely thanks to Liquid Wrench spray, but it had an annoying rattle.

However, I was unable to remove it without risking damage to the assembly, so I simply repacked it with lithium grease and that took care of the unwanted noise.

Once the housing was painted, I installed the new ignition switch.


installation videos

Since I replaced the aforementioned sector gear along with the key ignition switch, the following videos show the procedures with a standard C3 Corvette steering column out of the vehicle.

If replacing the key ignition switch is all you need to do, you can accomplish the job with the steering column in the car. You will still need to remove a bunch of stuff in order to get to it as explained at the beginning of this article, but you won't need to remove the column.

The sector gear should stay securely in place held by the lock rack and spring, and installation of the new key switch is just a matter of inserting the replacement part which should connect with the sector gear by simply pushing and locking it into the assembly.

I hope the following videos provide a better understanding of how all of these components work together to make the key switch installation easier.




In addition to the two videos above, there's a Part 2.0 video (below) available only to 76vette Blog readers. This may seem redundant, but there's no such thing as too much information on the subject.


Good luck with your project and thank you for following my 76Vette Blog!




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