So I’m trying to learn how the locks work on an 88 XJS, while trying to fix what’s not working.
The key works on passenger door and gas door, but not driver’s door. It seems like key is wrong. There is evidence of breaking in, so I’m wondering if an earlier PO had lock changed, and the key didn’t get passed down.
Id like to take out both locks and rekey. Easy to do?
Does it go in but not turn? Thats what mine does, and Im pretty sure its just crusted up inside
Did some more testing… When using the little lever to lock/unlock it, I can hear the solenoid clicking on/off, but there is resistance, so it won’t fully turn to lock. If I disconnect the rod from solenoid to lock, the door now locks/unlocks mechanically, and the disconnected rod moves fine.
Could the lock be jammed? I’ve sprayed a lot of penetrating oil.
I got the key to turn a tiny bit, so key is correct, but no luck. Me thinks the key barrel is fubared.
Greg,
Removing the lock is quite easy.
There is a U shaped clip that holds it, at the inside of the door, pull it out and the lock is out.
You can then dismount the barrel and see what’s wrong, and even modify it to fit your existing key if it doesn’t. Be extremely careful not to loose any of the little springs and parts.
The lock solenoid in order to work properly needs a certain amount of travel. I suggest that you disconnect it from the lock and then check again to verify if it works properly.
The latch mechanism can be removed by unscrewing the screws at the back of the door. On the bench it would be very easy to see what’s wrong with it.
Hope that helps,
Aristides
I see the C clip, but it’s right behind the window channel frame. I MIGHT be able to pop it off with a screwdriver, but I doubt I could get it back in.
So I removed exterior door handle. I saw the two nuts, 8mm. By removing window stop, I put window down an extra 1/2" giving me clearance for a wrench. Took it out in ten minutes. Putting it back will be much trickier!
Ok, took it apart, it fell apart on me, lost two springs, and have no idea how those teeth go in. Can I buy two new key tumblers?
Too late now, but a week or so ago I read where someone took something apart while the part was contained inside a zip-lock bag. Makes perfect sense. ( I wouldn’t have thought of it, either.)
So can I buy any key cylinder and fit it in? Or do I need Jag specific?
I don’t know the answer to that question.
Greg,
I have successfully removed, disassembled, rekeyed the locks for a different key, reassembled the locks, and installed them in my 1958 MK VIII and Series III XJ6s.
I have a bunch of those little springs in a box in one of my garage storage cabinets. Send me PM and we can work out the details.
As far as how to get the wafers back in correctly, you can remove one of your other locks that use that same key, disassemble it, note the orientation of the wafers, and then reassemble both in the correct order. I have done this successfully several times. You will need some patience, and small needle nosed pliers. Those wafers have several configurations to follow the cuts in the key. Getting them back in the correct order is important if you want that key to work in that lock again.
If you want some of those springs, just send me a PM.
Paul
Thanks Paul, I managed to find one of the lost springs, but I’m one short, and I think I’ll never find it. I’ll PM you, thanks. You seem to have everything 
I don’t quite understand how the wedges go in to make a specific key shape, they all look identical to me. I guess taking apart the gas flap key or trunk will reveal?
Greg,
Although the brass wafers may look the same, they aren’t. If you use a caliper to measure the width of the top and bottom of them you will find that they are different. The key pushes the wafers up or down against the small springs depending on the shape of the key cuts. When the wafers are all lined up properly on the correct key the tumbler will rotate in the barrel. If the key is wrong, or the wafers are installed incorrectly, the tumbler won’t rotate in the barrel. The differences in the widths may not be obvious to the naked eye, but if measured by a caliper they will be obvious. Seems to me there are 5 or 6 different kinds wafers, and each lock can have any combination of them in any order leading to thousands of different configurations based on a small number of wafers.
Paul
Yes, now I see, and they seem to be of different color.
Top is correct order from gas key. Bottom is me arranging door key to match by eye. I shall get micrometer to be sure.
Greg,
The wafers are made of brass. I suspect that they were all originally nice and shiny new brass but over the years they tarnished. I wouldn’t draw any conclusions about the wafers due to their color only on the measurements of their top and bottom widths, preferably by using a caliper because the differences are very small.
Paul
Ok, thanks for that info. Once I get the spring, and a new caliper (never had one) I’ll hopefully have lock working again.
I think the issue may have been, a PO put the cylinder in upside down!
Greg,
I have a vintage dial analog caliper that used to belong to my deceased father, that I like to use when working on my cars. I used to use an inexpensive digital caliper from Harbor Freight but much prefer the mechanical analog one. I found the analog caliper measurements to be much more repeatable, especially helpful on a time consuming task where the measurements matter, like adjusting the V12 engine intake and exhaust valves. I also don’t have to worry about batteries. My father was a parts inspector in the aerospace industry so it is a good instrument.
Paul
That must bring back nice memories when you use it.
My Dad didn’t work on cars or mechanics, so all my tools are my own. Unfortunately, I think my son will sell all my tools! 
Greg,
Put the wafers in in random order
Insert the key.
See witch ones are correct.
Rearrange the ones that don’t match.
Repeat until all wafers are flush with the cylinder when the key is inserted.
If one gives you trouble file it with a fine file.
One wafer missing is not a big deal, the lock will still work (but you could steel one from the glove box lock).
Best,
Aristides
Ha, thanks, but with 6 wafers randomly ordered, that’s 6x5x4x3x2x1= 720 possibilities!
I think I’ll go with Paul’s method and use a caliper 
This does bring up, that every 720 XJS’s, we have the same key!
