Repairing Worn Datsun Z Car Ignition Locks & Keys

Al Powell wrote: >Eric, thanks for your recent comments on pulling the 280 ignition switches. My 83 ZXT switch is worn enough that I can pull the key out while it’s running – it actually must be pulled back about 1/4″ to turn and often must be jiggled to turn on the radio, fan, etc. It’s clearly near the end of its service life. When this switch is changed, can the tumblers be transferred to the new switch to keep the key same as the doors??

Al and All,

Here’s my view and suggestions on dealing with worn Z car keys and ignition switches.

(you may also need to replace the electrical switch on the back side of the ignition lock, but I will not deal with that question here. It is a seperate problem that may be involved from what you describe above, but can be replaced later)

Z keys and locks often wear to the point that the key will slide out without resistance and even open another Z Car with ease. I used to shock a lot of my new customers by illustrating this fact with a little surprise. I would ask them if they would care for me to inspect their “new” Z car for any “unkown problems”. When they answered “Yes”, we would go out to the street where their locked car was parked. While they were trying to get out their car keys to unlock the car I would pull out my own set of 2 personal Z keys and insert them into the customer’s door lock. My guess is that 80% of the time I was able to open the customer’s door with no problem and was usually able to get into the car and start up his engine instantly with one of my 2 keys. I did this with new customers to illustrate how easy it was for a car thief to steal an older Z car. After my demonstration their car project priorities shifted from hot rodding to theft prevention rather quickly. Too bad I didn’t sell alarm systems at the time.

To renew everything to factory freshness there are several things that you can do.

1. Some Nissan dealers and repair shops have a special key making kit that can stamp out an original key shape as opposed to a copy, from a worn key. To do this the original key code must be known because it is used it to look up the proper cut out templates. In some 70-78 Z cars it is printed on a fragile, white piece of paper often glued to the inside of the glove box . I do not know if that is true of 280ZX’s. The dealer should be able to tell you. If you have an original factory key or ignition switch it may have that code engraved on it as well.

In many cases having one of these “cut-out” Z keys made will improve your situation noticably. Do this first.

2. If your tumblers are badly worn or the ignition switch is becoming quite sloppy you may be able to have a locksmith that specializes in automotive locks, disassemble your switch and install brand new tumblers for approximately $25. – $45. The new tumblers that he uses will be the same length as your old ones and will allow you to use your original key. That beats the cost of a new Nissan switch which lists for around $175.00.

If you do not get a fresh, “cut-out” key stamped out first by the #1 method you may still have problems, because a key copied from a worn original and then used with new tumblers may still be loose and slip out. With luck the locksmith will know how to make you a factory “cut-out”, but they are not always authorized to have the Nissan key kits.

3. The last consideration is to have a new ignition key that fits both of your doors and hatch as well. The above approaches will usually get you there, but be advised that door locks sometimes wear out at a peculiar point. Not inside the tumbler mechanism, as many would suspect, but at the back of the lock where there is a pressure point on a half circle section of soft metal that must rotate the door locking lever mechanisms. Very hard to describe in words, but when this metal area wears too far the key turning in the lock will no longer be able to either lock or unlock the door. You can not repair this problem. If you buy new door locks you will again be faced with the problem of not having a matched set of locks to one key.

Your other main option is to buy an entirely new, Nissan matched ignition, door and hatch lock setup from the dealer or MAS. Very pricey, but very “tight”. Unfortunately, a Z thief’s badly worn key may still be able to open a few Z’s with new locks installed so be sure to take other precautions as well.

I hope this answers most of your questions and then some. Eric Neyerlin

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