Key Codes..Again

[Bronze]

I know this topic has been discussed before, but i have not found a conclusive answer.
I need to make a new ignition/door key for my 1955 eldo. I have try out keys that turns the ignition lock but not the doors. Try outs are cut "inbetween "the correct cuts to allow them to work for several different codes. I know i could find the codes on the door handles, but being lazy i thought i would find it on the ignition cylinder, which i can remove with the Try out key. But..i cant find the code on the ignition cylinder! Should it not be there on a 1955?
BR
/Martin

[TJ Hopland]

If you have the skills to understand cut codes and can get the cylinder out can't you just look at the pins/wafers to know for sure what the code is?   With them out you could also get an idea if wear is a factor?

And for those playing along there are 3 things called codes involved in a lock...   and I'm no real locksmith so don't quote me....

There usually is a code that indicates the type of key blank.   Like in the 70 & 80's GM used a single letter and would rotate through the different ones year to year and through the different makes.   This is the physical size and length of the key blade and where the slots are that help it align with the lock.

There is then the cut code which directly tells you how deep each cut is.  If you know what type of lock it is you will know what the different cut options are.   Lets say this is a huge lock with 1 mm differences in the cuts and each pin has 7 options.    Say our code 1,3,0,7.   First notch or cut would be 1mm deep.  Next is 3mm.   Next is no cut at all and final one is 7mm.    That may not be a 'legal' cut with that 7 just because being physically next to the 0 may be too big a jump and would make the key stick but that's why a good locksmith makes the big bucks. 

The 3rd type of code is something GM in this case makes up and requires some sort of chart.    Maybe the code is A3M.   GM and maybe approved locksmiths would have access to this chart and be able to look up that A3M equals our 1,3,0,7 cut code.     That code could be something someone (or computer) literally wrote down as cars or locks were assembled.   It could also be something that is crackable like people just figure out that a 1971 Cadillac will always have a 1 for the first cut and maybe a 72 has a 2.   The rest of the letters or numbers are then also some sort of sequence you can decode if you have the 'key'.   

[bcroe]

My lock experience is from the early 60s to the early 80s, but I am pretty
sure the same lock technology was in use over many more years than that.
The key letter designates the groves cut into the blank, which must match
the groves in the rotating part of the lock.  The 6 tumbler or cut positions
each must have the key cut and lock tumbler matched, a number stamped
on a lock may be looked up to determine the cut depth of each position.  It
started with 4 depths (4096 possibilities), but was later extended to 5 depths
at restricted positions that would not affect the strength of the key too much.
A lock can be taken apart to determine the cuts, a key just measured. 

The outer fixed part of a lock has had very few variations, with the exception
of dash or column lock.  4 decades ago I just changed out the rotating and key
combinations so that all my cars use the same pair of keys.  good luck,
Bruce Roe

[Daryl Chesterman]

 I found the following on a locksmith website:

     General Motors

GM experimented with a double-sided key system for 1934-1935 and key blanks are no longer made. From 1936-1966, GM used a six-cut sidebar lock system with Ilco key blank H1098LA and code series 8001-9499. A set of 60 tryout keys was available to unlock these sidebar locks. The ignition lock has a poke hole in the facecap. Turn the ignition counter-clockwise to the accessory position using a proper tryout key. Insert a pin or bent paper clip into the poke hole to depress the retainer, then turn the cylinder slightly further counter-clockwise and remove the cylinder. Key codes are stamped on the plug.

GM door locks from 1936 to 1949 used an exterior retainer clip which was located under the door weather stripping. Pry the retainer outward with a screwdriver and the lock cylinder can be easily removed. Key codes are stamped on the housing. GM changed to a pushbutton door handle in the 1950s which had the cylinder mounted in the push button. A large retainer hidden behind the outer weather stripping was used. After dislodging the retainer, the door handle can be removed. Key codes are stamped on the shaft extension.

While GM has used many different glove box lock shapes over the years, many of them have a similar basic design. Picking skill is required. The lock must be in the unlocked position. If it is locked, pick and turn the plug clockwise one quarter turn. Next, compress the locking bolt downward as far as it will go and simultaneously pick the plug clockwise one quarter turn. The plug can now be removed. Key codes are printed on the side of the lock plug.

In 1967 GM changed their lock system, adding one more depth and began using various lettered keyways. Key codes were stamped on lock cylinders until the early 1970s. After that time only the ignition lock contained a key code.


It sounds like you must remove the lock cylinder from its housing to find the key code for the ignition key.

Is it possible that someone has changed the door locks and the ignition key doesn't fit the door locks?  The above article explains how and where to find the key code for the door locks.

Good luck!
Daryl Chesterman

[Bronze]

THanks guys,

I have try out keys that allows me to turn the lock and remove the cylinder.
I have a Curtis cutter and code book. So i can cut to code if i have the code.
I do understand the logic of he 6 cuts and their different depths.
I don't possess the skill to look into the key hole and determine the wafer length. And i want to avoid disassembly of the lock as i am sure i will lose a spring or a wafer in the process....
So with the cylinder in my hand i can't see any code, is it printed, stamped or was it no longer marked on the 1955 ignition, just on the door handle shanks...?

[Bronze]

Apologies, I re-read Daryls post, which confirms that i should find the code on the cylinder and it should be stamped...Guess the cylinder has been changed at some point in time.

[MindStorm]

I hate it when I have key problems. Your problem is solvable; you can turn to professionals for a solution to this problem. The last time I had problems with the keychain from my merc. I was hoping that the battery just ran out and tried to figure it out on my own. I found a video on YouTube, how to change the battery on the keychain and did it. As a result, the keychain did not work. It wasn't the battery at all. I had no choice but to contact https://www.carkeyduplication.com.
My problem was solved very quickly. Now I wonder to myself why I didn't do it earlier. 

[Cadman-iac]

 As far as I know, the only place that you will find a code is stamped on the passenger side door handle. It's stamped into the shaft that extends from the pushbutton/lock. There is no code stamped on the ignition cylinder or the driver side lock shaft.
There is one on the trunk lock, but I don't remember if it's on the lock cylinder housing or the shaft that extends to the latch.
You cannot look inside a lock cylinder to view the depths of the key cut needed. The indicator for the necessary cut required for any given tumbler, or wafer as someone else referred to them as, is actually located on the long edge of the tumbler that rests against the sidebar. It's just a very small "vee" notch in the edge of each tumbler at differing heights in this edge, which, when the key is inserted, will raise each tumbler to the matching height of cut on the correct key. Once all the tumblers are moved the correct distance by the key, and the notches are all lined up, this allows the sidebar to retract and the cylinder to rotate, either locking/unlocking a door or starting the car.
  It is possible to "read" the tumblers, but it requires the removal of each one in order to see that notch. And the length of this long edge of the tumbler is only about a quarter inch, so the difference in each notch location is miniscule, requiring a good eye. And if your lock is dry and gummed up with old lubricant, the tumblers won't come out easily. And, if you do get them to come out, you will need to keep them in order, or you have just lost your cut order.
As you remove them, you will need to keep track of which position each one was in, and the easiest way to do this is draw out a diagram of the key. Remember that the key hits the last cut first. The tip of the key doesn't reach the corresponding tumbler until its fully inserted.
Your Curtis cutter will start cutting at the head of the key and work outwards until you have cut all 6 positions.
So when you lay out your tumblers, do it so that they match the key as it's sitting in your cutter when you're holding it in the position you would as you are cutting, not as you are inserting the key into the cutter,as you will hold it in opposite direction to insert the key.
So when you dial in the cut code you are looking at the key with the head towards the right if I remember correctly. If you have a cutter, you will understand what I mean.
This will make it easier to visualize everything, and help you keep from wasting blanks by cutting it backwards.  (Ask me how I know that).
There is also the issue of the retainer that keeps the tumblers and springs in place. In most cases, it cannot be reused. It's a press fit piece that has a couple of small barbs on each side on each end. The barbs usually are not damaged in removal, but the top of the retainer is usually bent in the process, making it hard to return to the correct shape. If it's not correct, it will catch on the inside of the housing as the cylinder rotates, and more often than not it will jam up and not allow the cylinder to turn further. In the worst case scenario, it will move out of place and let the springs loose, which will destroy them and jam your cylinder.
So if you're going to attempt this, I would suggest that you visit a locksmith shop and inquire about purchasing the necessary parts to do the job. There are some that will sell these items to you.
I have a small collection of spare parts that I bought and some that I took from old locks. The tumblers can be reused as long as the area that rides on the key shank is not worn. And in some instances, the cut depth is actually stamped into the side of the tumbler, making identification much easier.
That concludes today's lesson in lock technology.

  I might add that I recently removed the door locks and ignition switch from my 55 parts car, and the only thing with a code was the passenger side lock shaft.
This matches what others have said about this subject in past threads.

   I hope this has been helpful and enlightening, illuminating, gives you some insight, shines a light on a dark, secretive business, opened your eyes, put ideas in your head, or completely talked you out of ever attempting this sort of thing.

  Rick

  Edit: I need to make a correction here. It's been a while since I looked at my Curtis cutter. The key loads from the left, not the right, and when you flip it over the key head remains on the right.

Something I forgot to mention too, is that when they are making the keys and codes, the cuts only jump up or down a maximum of 2 numbers or levels. Anything more than that and the key will be hard to insert and remove from your lock cylinder.
And here's a few pictures of what I'm referring to for those of you who are not familiar with these cutters.
  The last one is the tumblers laid out in order they were removed from the 55 door lock I just took apart. They typically don't look as nice as these, I brushed them up some to clean them.
If you look closely at the left edge of each one, you'll see that notch I referred to. This key cut would be 133132 if I assemble it back the way it was.

[bcroe]

. I hate it when I have key problems. 

That was how I felt about transmission problems. The problem was
solved by learning to rebuild TH400s (easier than you might think). 
The benefits have been huge for 4 decades. 

Did the same with locks.  Grab some junk yard parts, pick up
more on the internet.  I rekey a car an attendant parked, so the
trunk (or gas cap) could not be opened with his key.  My 5 cars
use the same 2 keys.  good luck, Bruce Roe

[Cadman-iac]

  My 5 cars
use the same 2 keys.

  That's the same thing I did with 4 of my vehicles with one exception.  I made all work with just one key for everything,  doors, ignition, tailgates, and glove boxes.
I got tired of looking for the right key in a parking lot or the rain.

   Rick

[Bronze]

THanks for all the answers, Rick in particular for confirming that i should not expect to find a code on the ignition lock.  I removed the passenger door handle, found the code and cut the key and it works in both doors and ignition
BR
/Martin

[David King (kz78hy)]

Here is photo of the door lock key code on my 55 Eldorado.  I used this code for the ignition and door key and had the trunk lock code off that key cylinder.  I ordered keys from Joe Jesser (CLC club member) using those codes and the key work perfectly in the locks.

I had to sets made, one w/the Cadillac V's stamped on the back, $$$$. and a regular set of the Briggs & Stratton blanks.