Hi,
I got my mk1 and found out that speedometer doesn't seem to work. Have anyone of you got any idea ? What should I do or where should look for a fix ?
Thanks in advance.

Cheers

rev counter works?
have you checked if its fitted good on that cable behind it

rev counter and all other meters except for speedo works fine.. is there a cable behind the meter or is it a sensor which counts the speed ?

mhm, dunno on 75 but my 55 has a cable, remove 2 bolts and look behind it

P75 can be either cable or sensor on a left hand drive car and sensor only on right hand drive car as far as i know.... No idea what side it will be on in Sri Lanka but guessing left.

Look in the bay to see which its got.. But my guess would be the plastic worm drive - both cabled and sensor systems use the same plastic worm drive. Its part number 7754073

But before you go buying one you need to find out if thats the issue - if its cable driven you can just pop the clocks out and then drive round the block and you will see that the cable is or isn't turning. If it turns then either the cable isn't on the back of the clocks properly or there is a problem with the clocks themselves.
If the cable doesn't turn then unscrew the sheath from the gearbox end and turn the cable by hand and see if its stuck or turns and if it turns get someone to watch the other end to see if its turns there (if not broken cable). If it turns freely and isn't broken its more than likely the worm drive - you should see the very top edge of the worm drive once you unscrew the cable. You can jack the car up and stick it on some axle stands and then start it and put it in first so the wheels spin and then go look at the point the cable slots and screws onto and see if the bit of plastic is spinning - if not its snapped (its got a weak spot where there is an o-ring).

If its sensor driven you can whip the sensor off and turn it and it should register on the clocks - if it does register then its not being turned by the worm drive. If it doesn't register then it could be the sensor itself or the clocks. I'd try new sensor first in that case.

The worm drive is number 10 on this diagram, just for info

so that sprocket is called worm drive, another mystery solved

we bow down to blu:worship::worship::worship::worship::worship::worship::worship::worship::worship::worship::worship::worship::worship:

lol, i have changed far too many of them worm drive thingys its not even funny.

blu73 said:

lol, i have changed far too many of them worm drive thingys its not even funny.

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no joke, i rly didnt know how its called

Damnn blu73 you indeed are a genie.. you know inside out of this.. We have right-hand steered vehicles in Sri Lanka and mine has a speedo sensor. Firstly I need to locate the sensor and check for it.. Once having a look I will get back and comment my findings.

Thanks guys for the fantastic help. You guys are awesome !

Its kinda down the bottom but on the top edge of the box if that makes any sense at all... On a cento easiest way to get to it is from underneath, on the punto there is more space so you can maybe go in from above, never tried it on punto myself though...

Its here (PS. How epic would it be to have a box that clean and shiny!!!)

blu73 said:

Its kinda down the bottom but on the top edge of the box if that makes any sense at all... On a cento easiest way to get to it is from underneath, on the punto there is more space so you can maybe go in from above, never tried it on punto myself though...

Its here (PS. How epic would it be to have a box that clean and shiny!!!)
View attachment 155301

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new one is shiny
i saw on eper they got prices for new gearbox, can you actually order that?

not that shiny, pretty sure that one has been polished..... I have worked on brand new fiats and the engine and box are not that shiny. Clean yes, shiny no.

There was a guy in the cento section that fully polished the gearbox housing - extreme lengths i'd never go to, looked cool though.