VDO Clock Repair (incl pictures)

[Motten]

Just want to say how grateful I am over this article. I followed the instructions step-by-step and now the clock works again!

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911 SC -82

[mark944T]

I have a 1974 911 and you can hear the clock running but the hands don't move. Is this a capacitor problem, a broken gear or something else?

[_baudett]

same as above, thank you very much for sharing. I have to clean the glass on the inside in another and did not know how to disassemble. Regards

[RedCoupe]

Originally Posted by mark944T

I have a 1974 911 and you can hear the clock running but the hands don't move. Is this a capacitor problem, a broken gear or something else?

Remember, it doesn’t have a second hand. What looks like a second hand is for recording a time or something like that. So, check it over 15 minutes or so and see if the other hands aren’t actually moving.

[mark944T]

I let the clock run for a few minutes and no movement. I hear it running but no hands move. If the capacitors are bad would the clock still sound like its running?

[mark944T]

I should state it’s a quartz clock.

[Hx911]

@ PRE-H2O
I had the same problem - the bearing-pin(s) of this gearwheel broke off - no idea where to get a spare. I contemplated some repairs to this, but fortunately a friend had a spare clock in bad cosmetic condition that he let me raid for parts.
Still would like to get that gearwheel though, to make the second clock work as well, somebody may need it one day

[Hx911]

Originally Posted by mark944T

I let the clock run for a few minutes and no movement. I hear it running but no hands move. If the capacitors are bad would the clock still sound like its running?

I had this problem, to the point where it worked sometimes, but then stopped. Made the proper noise, but no movement. When I opened it it looked like the picture PRE-H2O posted, well my gear was hanging in there with one pin still attached, that's why it worked 'sometimes'

[mark944T]

So nobody sells the gearwheel for these? I just throw it away?

[gptom]

you can try Seattle Speedometer to see if they would sell you the gear. Or send it to them for a rebuild

[Arminho]

Originally Posted by PRE-H20

I'm so far down the rabbit hole I cant see daylight!

and I have no idea what I am doing or what I'm looking at ! geesh!

I knew knew KNEW this wasnt going to be easy!

Sooooo I got it taken apart.....

When I took it apart the little orange gear EITHER fell out or I somehow knocked it loose, I was very careful taking it apart though.

No one mentioned the pictured little brown washer OR that lil black sponge looking thing pictured. All that is normal right?

The little BLUE cans are the ones that I am supposed to replace right?

Any insight/help on that little orange gear? (there are no broken parts I can see and nothing else fell out)

Just took my 74 VDO clock apart because it wasn’t running and I heard something rattling inside as I desoldered the earthing pin.

Turns out the same exact gear was loose in my clock!

[911 SLANT]

I was lazy to do all that tinkering and just replaced my inside with a AA battery operated clock. I also wanted to make it a Silver Dot to match my gauges.

[RDM]

OK, so the capacitors are evidently not the only failure mode.

My clock ran perfectly. Some months ago I took out the clock to install a Rennline phone mount I bought cheap on the board. Why? I don't use the phone in the car. Well, because it was cheap. So on reinstallation, the positive clock lead touched the (already grounded clock case, made a little spark, blew the fuse, and that was it.

The clock ran intermittently from that point. I consulted my favorite forum, found this thread, replaced the capacitors, and reinstalled. Unfortunately no change in behavior. The clock ticks always, but when it ticks loud the hands move, and when it ticks quietly they don't. At this point, they mostly don't.



So does anyone have a spare mechanism? A spare clock? I know I can replace capacitors now....

[jbell959]

Those of you with the 1974 clocks, I've looked around and I don't think there is a source for the gears. I've seen many of these clocks with the same broken gear. The 1974 clock is unique because it's the first year of the quartz clock but the movement was only used for about a year. The 1975-1989 quartz clock movement is completely different as you can see in the pictures. The case is even different so a later 75-89 clock movement can not be installed in a 74 clock case.

For the 75-89 clocks, the typical failure is the capacitors. If the capacitors are replaced and the clock still doesn't work it is most likely the IC that is bad. In any case, these clocks are not made to repair. Other than replacing the capacitors there isn't much else that can be fixed.

A while back I purchased some VDO movements that fit the 75-89 cases but require a slight modification to the connections to work with the 911 clock case. I can check if I have more if anyone needs one.

[RDM]

Originally Posted by jbell959

I can check if I have more if anyone needs one.

Well, I think I do!

[SorenDK]

Originally Posted by 911 SLANT

I was lazy to do all that tinkering and just replaced my inside with a AA battery operated clock. I also wanted to make it a Silver Dot to match my gauges.

This sounds interesting - can you perhaps elaborate a bit on this?

Thanks from Soren

PS: Have a 1974 with a broken gear so is looking to replace with something on AA batteries :-)

[stormin48061]

I would be interested to hear about the AA battery.. mine died the quiet death this summer... thanks PP.

[fanaudical]

Bumping this excellent post.

The clock in my '75 quit advancing the hands last night. I have removed the movement from the case. I hear noise when applying power to it but do not see the little motor turning. Is this indicative of capacitor failure? Or should I pull out the oscilloscope and start looking for other failure points? Anybody have a circuit schematic for these?

[jbell959]

Can you post a couple of picture of your movement. There are 2 different types. Typically you won't hear anything if the caps are bad

[fanaudical]

Mine looks just like the one shown in post 31.





Thanks for the help.