odd speedo jump

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edoh
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odd speedo jump

Post by edoh »

speedo - works reasonably well -
slight wobble - but generally pretty accurate -
oddometer doesn't work at all -
over last few days - whilst sitting stationery at roundabouts/traffic lights -
the speedo starts to click (!?) and move of its own accord ?! -
goes click - and jumps backwards and forwards - between 0 to 10 miles per hour - !!
then resumes normal working once we drive off -
i know its halloween time and all that -
but hoping for a more rational explanation :)
any ideas/comments gratefully received -
edoh
Owner of a red T25 fixed hi top campervan - colour - spikey red - petrol - water cooled - 1.9 dg engine rhd - 1990 g reg n still going strong!-
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ghost123uk
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Re: odd speedo jump

Post by ghost123uk »

edoh wrote:speedo - ... whilst sitting stationery at roundabouts/traffic lights - the speedo starts to click (!?) and move of its own accord ?! - goes click - and jumps backwards and forwards - between 0 to 10 miles per hour - !!

Spooky :shock:

And as I am sure you know, the speedo is purely mechanical, being driven by a cable off the nearside front wheel directly to a disk shaped magnet inside the speedo, where another disk shaped magnet attached to the needle and restrained by a tiny coil spring, transfers the rotary motion of the first disk into the angle of the needle on the dial. Whilst I am not saying it can't happen, as it obviously is, I am blowed if I can think of anything that could cause it :?

Interesting...
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AdrianC
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Re: odd speedo jump

Post by AdrianC »

Sounds like the cable's sticky and getting wound-up internally. Then it's releasing itself in spurts, which is causing that flick of the needle.

You could try and lubricate the cable, by pouring some light oil down from the top end, but I suspect the only real fix is a new cable - not that big a job, at least on LHD - I've not done a RHD one.
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MidLifeCrisis
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Re: odd speedo jump

Post by MidLifeCrisis »

FYI - if you do change out the cable - don't just yank the old one out then spend hours trying to prod/poke the new one into place (as I did). Tie some cord/sting to one end as you pull it out so that you can use the string to pull/guide the new cable into place - will be a lot easier.
Also, although it does need to be secured in a couple of places along its length, make sure that it is secured lightly so that the cable can rotate easily in its outer.
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edoh
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Re: odd speedo jump

Post by edoh »

3 excellent replies -
thank you peeps -
will try the lubrication first - then a new cable -
n see from there -
thanks for your contributions :)
edoh
Owner of a red T25 fixed hi top campervan - colour - spikey red - petrol - water cooled - 1.9 dg engine rhd - 1990 g reg n still going strong!-
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