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Mechanical VDO Speedo problems
Roman - 2/4/09 at 01:00 PM

It reads the speed perfectly, but the odometer is not working

Any suggestions?

Mr Whippy - 2/4/09 at 01:07 PM

One of the little cogs might have came adrift. Their easy to dismantle, just lift the needle past the stop post and mark the natural position it sits when the gauge is horizontal (if there’s not one already) then pull the needle off. The faces are usually only held on with 2 screws and then you can see right inside it. The counter will just be screwed on too. Once sorted, pop the needle back on over the mark and lift the needle back over the post and it will still read the correct speed.

here's a linky that shows how to take a speedo apart, their all pretty much the same kind of idea

[Edited on 2/4/09 by Mr Whippy]

Roman - 2/4/09 at 01:29 PM

Cheers Mr Whippy your a star.

Lets hope it's just that then. :pray

02GF74 - 2/4/09 at 01:58 PM

I'd be wary about removing the needle; all the speedometers I have taken apart (mostly smiths + 1 mysterious czech made one), the rear can be gotten to by removing it from the can, no need to remove needle.

I say this since the need is tensioned by a spring and I think (not sure) that if positioned differently - hence Mr W saying to mark it - the speed will not be displayed correctly due to a higher or lower spring tension.

Secondly I found that it is not possible to remove the needle without damage to the needle.

you have been warned.

anyways, back to your problem. Inside is a worm drive that is taken off the cable and this will then turn one or two small gears for the odo. I cannot see how these can come loose so you may find somehing has popped out of place, bent, broke or worn teeth. Some of these may be repairable, some not.

note: odometer is not tested for SVA.

[Edited on 2/4/09 by 02GF74]

Roman - 2/4/09 at 03:00 PM

Next question then, if something is broken is it possible to get spares?

And, do I by law have to keep a record of my mileage for insurance purposes, etc?

Daddylonglegs - 2/4/09 at 03:58 PM

I've recently bought a VDO mechanical speedo and took it apart to zero it. If it's the same as mine, there is a plate on the side of the mechanism that swivels (it's screwed in place) against the worm drive for the odo. Maybe that has come adrift?

HTH

damajin - 3/4/09 at 08:35 AM

quote:
Originally posted by Daddylonglegs
I've recently bought a VDO mechanical speedo and took it apart to zero it. If it's the same as mine, there is a plate on the side of the mechanism that swivels (it's screwed in place) against the worm drive for the odo. Maybe that has come adrift?

HTH


That's exactly what happened to mine, the connection from the worm drive to the odo is sat on a small rail which allows it to be positioned (a bit like an alternator) then fixed with a screw, this had worked loose and hence the speedo worked fine, but the odo did nothing. Mine is a VDO too so it look like this may be a common "feature" of these speedo's.
Only took about 20 mins to strip mine back to zero, re-grease everything, add a little thread-lock to the screw holding the odo gear connected and put back together, and no need to remove the needle!

Good luck with yours.
D

Daddylonglegs - 3/4/09 at 08:58 AM

Took me around 30 ses to zero mine. Just knocked the pin back holding the white cogs over the odo wheels, zeroed them then replaced....Voila!

One of the guys at work thought it was a bit dodgy zeroing speedos until I explained why