Odometer not working

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petethefeet
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Location: South Bucks

Odometer not working

Post by petethefeet »

Hi all,
This is opposite to another thread recently.
Speedo needle indicates the correct speed (as close as it has ever been) but the odometer has stopped working, this was found after the winter lay up so I assume it is stuck.
Is there any documentation to show where is seized or jams so I can try to free it?

thanks for your help

Pete 
1982 2 litre CU Auto Devon Moonraker called Brian

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AngeloEvs
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Re: Odometer not working

Post by AngeloEvs »

There is a lot of information regards this problem on the internet and various solutions.  What frequently happens is that the Odometer drive gear is no longer meshing with the worm gear and drive is lost to the milometer tumblers.  The Gear is just a friction fit on the Tumbler shaft and, for a different reasons, moves outward.    In the picture below you can see an aluminium section has been added and this prevents the gear from movig outwards but first you have to gently tap the gear back so that it meshes with the worm gear.  

You will need to remove the speedo assembly and look to see if the gear is meshing and that there is no play when you pull or push the gear. 

 
You will find various solutions (some easier than others) but my advice is try the simplest first as these do not require the speedo to be dismantled and  avoids breaking the needle or damaging the shaft when trying to separate one from the other.  

Use a small socket, one that just fits nicely over the gear and tap it gently, you can add a tiny drop of super glue once in position but take care that it does not run into the mechanism or the tumblers.

You will also need to check the gear has not split so look for signs of an hairline crack.    Also, check that the shaft is not corroded and that the litlle black gears under each tumbler are free to rotate, spray a little bit of WD40 around the area to keep everything moving.    Finally, you will need to come up with a method of preventing the gear sliding outwards which is the function of the small aluminium plate you see in the picture, this is simly attached to a plastic post using a very small self tapper.

If after doing all of this the gear still slips then its a case of removing the gear and putting a small ridge on the shaft to bind the gear and tapping the gear back onto the shaft.   More info on this approach if you just Google 'T25 Speedo repair' or similar.   Might be in the Club WIKI but haven't checked that.

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1987 DG Karisma LPG with remodelled interior

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