Fixing your Z clock

[monkeyman]

Hi all,

There has been some discussion about how to go about fixing the clocks that are driven by the small electric motor. I managed to fix the type that are driven by a small electric circuit. I promised to write up something and post it. I finally did it. I couldn't help myself from drawing up a few things and trying to make my little write-up look nice. I was pretty happy with it and showed my wife last night. She called me a nerd! How do you like that?!

I have attached it (hope this works)

If anyone has any corrections or comments, I would love to hear them.

Eric

How to fix your 260Z or 280Z clock - rev 1.pdf

[ChrisA]

Hi Eric,

I am so glad you posted this. I've got one of the Citizen calendar clocks that doesnt work and its driven by the same circuit board as in your article.

Thanks VERY much for this, I am off to the electronics store.

Chris A.

[ChrisA]

Eric,

I did find another equivalent to the C828 transistor. It's NTE Electronics NTE229 transistor. But they are based in New Jersey USA so that might not help the folks down under.

I buy a lot of stuff from www.mouser.com and they have a great cross reference system.

Again, thanks for the article.

Chris A.

[Arne]

Great write-up for the electronic clocks. Good job!

Admins - can this thread maybe be moved into the Tech Articles area?

[EScanlon]

Excellent write up! Probably as good as you'd get out of a laboratory!

One note however, the Early clocks weren't of this type. This is the second series of clocks, but I'm not sure if they were specific to the Series III or IV. I won't speculate if the Series II weren't mixed either. However, all the clocks I removed from earlier series cars (70-72) didn't have any electronic components. The only way I found out about this style was when I was given one of them.

I can't be absolutely sure of when the change happened as it takes disassembling the clock face in order to peer inside.

But, it is still one of the best write-ups I've seen. Maybe change the title to reflect the electronic components in the interior to differentiate from the one that just deals with the gears / springs.

E

[MikeW]

There has been some discussion about how to go about fixing the clocks that are driven by the small electric motor. I managed to fix the type that are driven by a small electric circuit.

One note however, the Early clocks weren't of this type.

It looks like he already knew that.

I agree; excellent writeup. I wish that my clock (9/71) wasn't mechanical since I didn't have much luck fixing it going the sewing machine oil route.

[EScanlon]

Mike:

Check the title of the .pdf file.

E

[Zak's Z]

Hey..good write-up. The pics help. Now we just need a similar write up for the EARLY clocks I guess!

Zak

[monkeyman]

Good point, I could have been a bit clearer on which clocks it applies to and how to tell before you pull them out of the dash. From what I have been able to tell (and this was not a thorough investigation), the earliest clocks were motor driven. They changed to the electric circuit driven type in 1974 I think (I have seen an early 260Z with the motor driven clock, and my 1975 260Z has the electric one). So unfortunately, this article wont help the 240Z owners out there.

There is an easy way to tell. The motor driven clocks have the manufacturer name 'JECO' stamped on the face. The electric circuit driven clocks have 'Kanto Seiki' stamped on the face down the bottom (look closely, it is partly obscured by the housing).

These are the conclusions I came to after tinkering with 1/2 dozen clocks. It also might be different here in Australia to elsewhere (though I don't see why).

I think I will update the article, but will first wait to hear any other suggestions or criticisms. (Chris A has already mentioned a different clock this article applies to, and has found another equivalent transistor.... let me know if it works Chris).

Eric

[EScanlon]

Zak:

Although not up to the technical expertise of this post's write-up, here's one article for the mechanical clock, JECO.

http://www.classiczcars.com/forums/showthread.php?t=18442

MikeW:

On a separate note, did you try tweaking the pivot points of the pendulum gear? The pendulum gear is the one that rotates one way then the other, there is also a small pin towards the center which "flips" a small lever one way then the other. This is the heart of the clock and what regulates the "tic-toc".

The pivot points are actually screws with an inverted cone to allow the gear axle pin to rotate and be held in place. If those screw pivots are in too tight, they will actually exert pressure on the axle pin and stop it from rotating freely. You want to just barely crack the screw pivots loose, while not unscrewing them so far that the pendulum gear falls out of position.

Try that, as that has been the only other thing that's prevented others from getting their clock to work.

Arne, how long has your clock been working now, since you fixed it? Mine is going on 4+ years.

E

[MikeW]

MikeW:

On a separate note, did you try tweaking the pivot points of the pendulum gear? The pendulum gear is the one that rotates one way then the other, there is also a small pin towards the center which "flips" a small lever one way then the other. This is the heart of the clock and what regulates the "tic-toc".

I'll have to try that. I had given up on fixing it and started a project to install a cheap quartz movement. I gave up on that as well when I couldn't use the original hands and had difficultly fabricating some that looked right - glow in the dark paint and all. :dead:

[Arne]

Arne, how long has your clock been working now, since you fixed it? Mine is going on 4+ years.

Several weeks now. Still gaining 3-5 minutes per week. I might have to try to slow it down some, but I'd likely go way too far, so I'll probably leave it as is.