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Mon Apr 23, 2012 6:08 am

Hi,
The odometer on my ’49 has stopped just before reading 62,000. I’ve taken the speedometer apart and discovered the small metal disc that turns the mile numeral barrel over every revolution is slipping on the shaft. The burden of turning over four mileage barrels from 61,999 must have been the last straw. I gather this disc is an interference fit on the shaft. Is there a way of getting this to grip the drive shaft? I have managed to pull the shaft out enough to get the disc off and was thinking I could gently tap the edge of the hole with a small centre punch enough to distort it slightly so that when I put it back into position and tap the shaft back through it will grip it. The construction of the mileage counter with folded over metal sides makes it impossible to disassemble properly. Is there an easier way to fix this drive disc?
Cheers,
Andy.

Mon Apr 23, 2012 6:46 am

a drop of loctite?

Mon Apr 23, 2012 7:01 am

I restore speedos and encounter that problem often. You idea will work, but be very careful how much you distort the shaft. Too much and you may crack the disc putting it back on.

In any case, I use a very small amount of JB Weld epoxy also. Just make sure you clean the parts with solvent first.

Mon Apr 23, 2012 7:49 am

Hi,
Thanks very much for that, thinking about it the wheel is cast and looks very brittle. I'll be reassembling it this evening so I'll let you know how it went :)
Cheers,
Andy.

Mon Apr 23, 2012 10:53 am

This happens a lot on late model Porsche speedos. As far as I know all VW and Porsche speedos except Baywindow speedos have the same pot metal disc up to at least 1974. So if you end up breaking it somehow, you can steal one from a late Beetle speedo etc.

Tue Apr 24, 2012 5:31 am

Hi,
Well I got the cast wheel back on the shaft but it was a real struggle with the limited amount of disassembly. I put some marks on the shaft with a small pair of sharp pliers and tapped the shaft back through the cast wheel. The marks were enough for the wheel to be a nice tight fit on the shaft. The biggest problem I had was lining up the mileometer digits so they were all in line and I’m still not sure they sit squarely in the speedometer face aperture. I’ll find out tonight when I put it all back together. Is there a good way to line them up? Will removing the shaft with little tumblers/pushers enable the numbers to be lined up properly or is that opening a can of worms with regards to the numbers turning over sequentially and in order? Thanks for all your help and advice so far!
Cheers,
Andy.

Tue Apr 24, 2012 8:48 am

mr magyar wrote: Hi,
Well I got the cast wheel back on the shaft but it was a real struggle with the limited amount of disassembly. I put some marks on the shaft with a small pair of sharp pliers and tapped the shaft back through the cast wheel. The marks were enough for the wheel to be a nice tight fit on the shaft. The biggest problem I had was lining up the mileometer digits so they were all in line and I’m still not sure they sit squarely in the speedometer face aperture. I’ll find out tonight when I put it all back together. Is there a good way to line them up? Will removing the shaft with little tumblers/pushers enable the numbers to be lined up properly or is that opening a can of worms with regards to the numbers turning over sequentially and in order? Thanks for all your help and advice so far!
Cheers,
Andy.

It is all about patience with those odometer wheels. When I restore speedos I very often reset the device to "00000". Unless the reading is already very close to "00000" (in which case I just use a drill on the odometer input shaft to advance or reduce the reading) I usually take the shaft out of the coupling gears and that allows me to individually roll the number wheels to where they need to go.

To remove that shaft, I run a small grindstone on the Dremel against one of the crimped ends. This make the shaft spin rapidly, but also slowly grinds the "lobes" of the crimped end. Once they are ground down enough, I slip the shaft out.

Once reinstalled, I put a blob of solder on the shaft end that I ground down. If you do this do it quickly. If you transfer too much heat into the shaft with the soldering iron, you may melt the coupling gears.

A few other tips:

1. Take pictures with your digital camera of everything BEFORE you take it apart. How the wheels set up and mesh, etc.

2. Put tape across the face of the number wheels as you get them lined up so they don't spin from where you set them as you fit the coupling gears back in. Start at one end and as you get the wheels lined up, press the strip of tape across them.

3. Test it by manually turning the odometer drive shaft (the gear right on the end of the number wheel shaft). Remove the coupling shaft to the speedo mech to do this. You done have to completely separate the speedo from the odometer mech to do this, you can just loosen teh screws holding them together a few turns and it will allow you to lift them apart a bit to free the coupling shaft.

4. If you do want to spin the odometer shaft with a drill, chuck a bolt with about a 8-9mm head in your drill, by its threads. Then use a short piece of rubber tubing about 7mm ID, slip it over the bolt head and over the odometer shaft gear. This is a good torque limiting solution in case something binds up, the hose will slip and fall off instead of destroying the odometer mechanism.

5. Patience, patience, patience!!!!

Tue Apr 24, 2012 9:14 am

I would love to see this process on your spycam.

Don

Tue Apr 24, 2012 9:31 am

sunroof wrote: I would love to see this process on your spycam.

Don

Well as it turns out I am doing a speedo now, will post pics next week or two....

Tue Apr 24, 2012 10:08 am

Hi,
Thank you very much for your helpful advice and replying so quickly. I'll put it into practice tomorrow evening...patiently! Your speedometer restoration will be very interesting to see, can't wait for the pics!
Andy.

Thu Apr 26, 2012 10:23 am

Make sure the little gears are facing the right way. The narrow teeth on the gears are offset to engage only one odometer wheel, the wide teeth engage two odometer wheels.

Thu Apr 26, 2012 2:22 pm

is there any lubrication required? If so... what do you use?

brian waz

Thu Apr 26, 2012 7:43 pm

bwaz wrote: is there any lubrication required? If so... what do you use?

brian waz

None is really required, although I usually put some machine oil on a paper towel or rag and just wipe the shaft before slipping the gears back on. I have seen people really mess up speedos by soaking stuff with oil and grease.