I've been an automotive locksmith for almost 35 years now, and I've used just about every technique and tool there is to make keys to vehicles at one time or another. Since I grew up making keys by impression, that is still my fall-back method when all else fails, but my 55-year-old eyes make that a...
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I've been an automotive locksmith for almost 35 years now, and I've used just about every technique and tool there is to make keys to vehicles at one time or another. Since I grew up making keys by impression, that is still my fall-back method when all else fails, but my 55-year-old eyes make that a little harder than it used to be. And then there is also the fact that I seem to be getting lazier as I age, or at least more frugal with my energy. Now, when I set out to generate a key for a car, I'm looking for the fastest and easiest method.
For a while there, it was almost too easy – just pick up a phone and get a code number from the VIN –but those days are fading fast. Today, when I have to make keys for a vehicle, the first tool I reach for is one of the new Kobra Readers shown in Photo 1. With the Kobra Reader, I can usually decode the door lock and / or the trunk lock in a matter of minutes, do a simple two or three cut progression in the ignition and I'm done. It sure beats the heck out of pulling door panels and ignition locks!
Most modern vehicles use a lock system that incorporates wafer-tumbler door locks and a sidebar or wafer tumbler ignition. In most cases the cuts that are found in the door lock will give you 60 to 80 percent of the information that you need to make the final key. If the car is equipped with a trunk lock, you can often get the rest of the information you need to make the key without even touching the ignition lock.
At this time there are Kobra Readers available for six different lock systems:
• Chrysler 8-cut / 7-cut systems
• Ford 8-cut systems using cuts 1 – 6 in the door
• Ford 8-cut systems using cuts 2 – 7 in the door
• Ford 10-cut system
• GM 10-cut system 75 groove key
• Mitsubishi 8-cut systems using the MIT 6 keyway
With these six readers, my work at the local auto auctions is a lot easier. When I need to decode one of these vehicles, I can generally have a working mechanical key made in just a few minutes, and then turn my attention to programming any transponders if needed.
In order to understand how the Kobra Readers work, it's necessary to understand the construction of wafer-tumbler locks. Photo 2 shows a typical wafer tumbler. The three letters each refer to a different part of the wafer. Each part plays a role in the operation of the Kobra Reader. Let's take a look at what these parts are and how they allow the Kobra Reader to decode the lock.
The section marked “A” in Photo 2 is the uppermost portion of the tumbler, and this part contacts the inner surface of the lock housing when the tumbler is in the “rest” position. The rest position is the normal position of the tumbler when there is no key in the lock. The pressure of the spring pushes the tumbler up until part “A” contacts the inside of the lock housing, at which point the tumbler can go no further. (The terms “up” and “down” as I am using them here are relative only to the photo and in reality the lock could be mounted in any position.)
The section of Photo 2 marked as “B” is the spring tab. The spring maintains tension between this tab and the base of the chamber that contains the spring. In the rest position the spring is as fully extended as possible inside the lock.
Section “C” is the lower portion of the tumbler. The width of this portion determines the depth of the cut on the key. The wider this portion is, the deeper the cut will be. It is this portion of the tumbler that the Kobra Reader measures in order to decode the lock.
Now, let's take a look at the Kobra Reader in detail. Photo 3 shows a GM 10-cut Kobra Reader. The slide is held captive in the unit so that it cannot get lost or damaged. Near the tip of the blade is the trap notch, which traps each tumbler in the lock, one at a time so that it can be decoded with the slide. When the tool is being used, the dimples on the side of the blade are used as a guide to determine which tumbler is trapped so that you always know exactly which tumbler is being decoded. The even numbered cuts are shown on one side of the blade and the odd numbered cuts are shown on the other. As shown in Photo 4, each Kobra reader features a high-intensity LED illuminator that surrounds a high-contrast scale to make decoding at night much easier.