GTV (principles may apply to other models):
First, you've got to remove the handle you want to re-key. For the '71, this was done for me 17 years ago, although on the '69 door handles from the rusty parts car i expedited the job with my metric Sawzall. You may want to choose a different tool - to each his own;-)
Once you've got the handle out, if you look behind where the tumbler housing is, you'll see a casing with a couple of springs on it, and a roll pin going through it. Remove the springs, and drive out the roll pin with a small punch. The tumbler housing then will come right out through the front. Be careful not to lose any of the tumblers as you remove it - they're lightly sprung.
BTW, there are different types of slotted keys which go into different tumbler housings - if the key you want to use doesn't slide right in, you need to find a tumbler housing which will accommodate the key. Once you've got the correct tumbler housing, the tumblers seem to be the same. Also, if my memory serves me correctly, tumbler housings are the same as in Spiders of that vintage (probably all Spiders).
Anyhow, looking at the tumbler from the side, with the tumblers in it, insert the key. Your goal is to get things so that with the key inserted all the tumblers are flush with the outside of the housing.
There are 5 tumblers, and what seems to be 3 different 'lifts', which is how much the tumbler moves when the key is inserted. If you look at the key, places that are not cut too deeply don't require a lot of lift in the tumbler to make it flush, places that are cut deeply require lots of lift to make it flush.
With the key inserted, if you have a tumbler poking out the top of the housing and another poking out the bottom, just try swapping tumblers (remove the key to swap tumblers, then reinsert). Just doing this worked on one of my locks.
It may be that with the key you are trying to use, and the set of tumblers in the housing, you won't have the right combination of tumblers to make things work. There are two things you can do here:
1. Have an assortment of tumblers handy
2. File the ones you have. This only works one way - if you are in need of a tumbler with less lift, you can file away on the inside of the tumbler. If you need more lift, you're s.o.l.
Once you're done, assembly is the reverse of disassembly.
Something to note, you may want to work on one side at a time, as they are mirror images of each other, including tumbler housings. If you go off in search of another tumbler housing, make sure all the slots in the housing are the same as what you're replacing; otherwise you won't get the full 180 degree range of motion in the key, and things won't work.
- Brian Shorey
Giulietta (principles may apply to other models):
I'm not an expert on this but I've taken several locks apart including my '59 Giulietta. And my brother used to be a locksmith. I guess I may have picked up some of this information up through osmosis.
Typically, automobile locks (ignition, doors, trunk) can be broken into two groups, wafer (newer) and pin (older). Both operate in the same manner. They ride on the bumps and valleys of your key to line up with the cylinder and allow it to turn (lock - unlock). Wafers and pins are spring loaded with small, and easily lost, springs. They are also interchangeable, meaning the wafers/pins can be moved into different positions on the cylinder, thus changing the key code.
I would not recommend that you attempt to re-key the ignition. Some ignition switches are held in place by special break-away bolts that must be drilled out to be removed. Also, there is the electrical switch component that complicates things. If the switch is broken... go for it, you have nothing to lose. If its is a good switch... use two keys (ignition & doors).
Separate door locks are straightforward to remove. They're generally held in place with a sliding retaining clip or nut. Remove the clip/nut and the link to the door latch and it should come right out. If the door lock is internal to the door handle, you will need to remove the entire assembly. Remove the lock that you will be matching the others locks to first.
Disassemble the lock buy placing the key in the slot, removing the circlip and sliding the cylinder and key out. If you remove the cylinder without the key, be careful that the springs and wafers don't fly apart. Mark the sequence of the wafers so they can be replaced in the same order. Examine the wafers, they may have numbers on them. If not, you will still use them to compare to. Now go to your supply of wafers and locate the ones you need.
I can't help much on where to get the wafers. I'm assuming that your GTV uses wafers. Maybe a locksmith (I'm sure they have lots of Italian lock catalogs to order from :-) , maybe from some broken locks you have lying around.
Now there is one more thing to be aware of... you don't need to have a wafer in every slot to have the lock still work. For example a five wafer lock will work fine with four wafers installed. You will have to make this call as the lock will be easier to pick. My feelings are that the lock will not appear to be any less capable of locking so a thief would probably break a window or use a slim jim anyway.
My recommendations: For re-keying the car: Take all the locks apart and use what wafers you can and leave the remaining positions without wafers. Broken handle with internal lock: Use the cylinder from the broken one in the new lock. Broken lock: Take it a part; if it's a broken wafer, remove the broken pieces and reassemble.
- Ron Lotton