So I just bought my first Z (Yay!) and it had the same lock issue, along with a bunch of other ones.

A slightly different solution worked for me, so I figured I'd share. Unfortunately, in all my excitement in getting it to work, I put everything back together before taking any pics, but will try to describe it best I can.

My lock problem was as described in this and other threads. The lock cylinder looked exactly like the one pictured in this thread. I didn't have any metal wire which I would trust to retain its spring constant in the long run to make the "wire hanger" repair last. I did have some softer metal wire; one of those shiny steel types you see at hobby stores. So instead, I drilled a hole right in the location where the lock cylinder lever arm is worn down (where the metal used to be, but is now gone). Drilled straight in, perpendicular to the shaft, about 2mm deep. Then jammed a small length of wire into the whole and compressed it in there with pliers. Matched the drill bit and the wire size closely so the wire barely fit and, upon compression, the wire expanded in the hole and pretty much stayed there for good. Then file the excess wire down to resemble the original shape of the cylinder and done!

If anyone wants more info, I can try to draw up some explanatory diagrams. (This probably makes a lot more sense to me than someone reading it)

Hope this helps.

So now I have three different keys for my car, but I can find them with my eyes closed, so I'm OK.

Yep me to but its all good!

I"m interested in seeing how the wire repair worked out in the long run. IMO, locks take a lot of abuse and wires bend, so I would expect the wire repair to fail. I think the only real solution would be to use locks made of a much more durable metal so the keyed holes don't wear out, or to redesign the locks so the arm is attached in a better way.

Edited April 13, 201410 yr by TomoHawk

Ran into the same problem described earlier in this post (that refuses to die!!!). My driver side door would lock with the key yet would not unlock. Not totally convinced that the hanger wire repair will be long lasting and wanting a method that (if failed) would still allow me to repair the cylinder via the FUA technique described before, I decided to try a different approach without the addition of any "parts".

The wear on the flat "shoulder" of the cylinder where the arm makes contact and pushes it to rotate, transforms that shoulder into a type of ramp which allows the arm to slide over that edge thus preventing rotation of the arm.  When I examined the worn ramp effect under magnification I noticed that the wear on the cylinder metal was truly minimal but the fact that the 90 degree (flat) shoulder was minimally altered rendered the rotation of the arm ineffective.  With the use of a fine diamond burr on the Dremel I shaved a minimal amount of metal at the base of the "ramp" transforming it again into a flat step, very similar in shape to the unworn one on the other side of my cylinder (the side used to lock the door). To my surprise, the remedy proved immediately effective mainly because the original shape of the "shoulder" is attained with very minimal loss of material (less then 1mm) and no extra parts (wire) are needed for the repair. Total cost of repair; $0.00. Now my cylinder locks AND unlocks the driver side door properly. Granted, eventually the cylinder metal will wear again but by that time maybe ZCar Depot will make replacement cylinders for the '77 and '78 Zs that can be keyed alike with the original Nissan keys.

Here are some illustrative pics:

Pic above showing the deformed "shoulder" on the cylinder (circled in red).

Ramp squared off and back to original shape with fine diamond Dremel burr.

Unlock side (left) and Lock side (right) are quite similar after Dremel work.

Lock arm back in position and working properly to either side.

Edited February 13, 20205 yr by dmorales-bello

With the hands of a surgeon!  I'm affraid I have the hands of a drunk stone mason.

Great job Sir!  

That’s awesome work and saved in PDF for when I next need to do mine - I have the same issues with unlocking!! Thanks for sharing [emoji106][emoji106]

 

On a slightly different note - I urge everyone to check their keys for this weak spot. A few years ago I was 150 miles from home and as I locked the car at night the key turned to chocolate!!! Thankfully the boot was still unlocked. The remains were easily pulled out of the lock with two small watch screw drivers though - but please check your keys!!

 

 

And here are pics of my spare key at the time and another member’s key who was at the same event!!!

 

 

Sorry if I’ve gone off topic a little.