Technical Sticking Speedo

[thisisburdett]

Happy New Year all,

Does anyone have any experience with a sticking speedo.
When I start moving it sticks at about 50kph and if I'm moving any faster it sticks at 70, however it doesn't move in between, and is already at 30 before I start.

The cable is fine, I'm wondering if it could be touching the clear plastic front of the screen which is causing it some resistance.
Any ideas?

Thank you!

 

[fiat500]

Worth double-checking that cable situation. It may be the inner drive cable weakened and getting wound up and then releasing continuously; or it might be sticking to the inner surface of the outer conduit.

I would check for kinks or tight curves and that the knurled nuts at each end are tight and the cable ends properly located.

Being such a long cable there's a lot of scope for things to go wrong with it.

 

[fiat500]

PS. Re-read your symptoms. Hmm! more likely to be what you suggest but i am no help with that having left that particular item well alone. Good luck with it.

 

[Bambino]

Does it make any noise - tick, tick, tick etc. ?

Chris

 

[thisisburdett]

Thanks Pete!

Not that I'm aware bambino, should it?
Thanks

 

[Bambino]

No - it should be silent. If it was making noise, it might help diagnose the problem.

Removing the speedo internals from the casing is not difficult, though repairing the mechanism takes skill - a skill, by the way, that I don't possess, as evidenced by at least one broken speedo in my parts bin

If you pull it apart, you may find whether it is binding or not. If you can get your hands on another cable or at least one that will fit the back of the speedo, chuck mount a drill on the other end of the cable and run it at low speed to check that the internals are functioning.

Chris