Technical Speedo jumps around..

[peterp]

Hi all
The speedometer on my 94 Uno jumps around a lot when driving-I reckon a cable needs replacing somewhere?
Any thoughts on what could cause this and likely cost to repair?

Cheers
Pete

 

[alexGS]

Start by removing the instrument cluster (see other thread about Fiorino dash removal) - and then just pull the inner part of the cable out, leaving the outer part in place. You'll want to handle it with paper towels etc. as it will be greasy. Clean with WD-40 or similar, then lightly apply fresh grease and push back into place, turning gently. It will be a little fiddly to re-fit to the instrument cluster, but the result should be well worth it. I haven't had to change a speedometer cable yet!

Also check in the engine bay that the cable runs smoothly down to the gearbox - straighten any kinks that you find.

Good luck!
-Alex

 

[peterp]

Thats great advice-cheers Alex

Pete

 

[(CZ)enda]

Applying some MoS2 grease will not hurt anything as well.
Just for possible further discussion - I am by no means a purist - I prefer thin penetrating oils (like e.g. Sviting) to the WD40.
I remember a flamewar on certain motoring forum about WD40 and, in the end, the conclusion was that although WD40 penetrates quickly and unseizes stuff etc., it has minimum lubricating effect.
If I remember right, it was reasoned that it was originally formulated for de-watering electric contacts and therefore it is not very efficient when one needs long-lasting lubrication.
But, as I mentioned above, I do not argue, anyway I quit using it.

 

[alexGS]

(CZ)enda, you are right about the WD-40 - I was suggesting using it only for cleaning, wiping off thoroughly before re-greasing the cable.

So we have no argument

-Alex

 

[peterp]

Hi Guys
I've just had a go at doing this following the advice above but its still doing the same.
Can see no kinks or anything.
Should the connection to the back of the cluster be a very tight fit as mine is round and doesnt seem to fit tight.Even tried wrapping some tape around it.


Pete

 

[M@nticore]

It must have a plastic slide that you slide over when refitted, maybe you cluster is at fault, but that is very likely, if you don't come right with the cable cleaning and lubeing the just replace it.

 

[jjhepburn]

It could (very unlikely) be the speedo itself at fault, its very easy to check it out.

First check everything from the cable to the diff is fine to do this you could remove the instrument cluster and just have the speedo cable stick out of the hole (where the cluster normally is). Then put the car in neutral and move it forwards, if the speedo cable turns smoothly then its probably the instruments at fault.

Now if you are keen you could try to pull the instrument cluster apart. The speedo is a mechanical thing with springs and magnets. Just check its not rusty or seized or anything. I have never heard of this being a problem before, but that doesn’t mean it cant happen. If it does look stuffed I would replace it since they are finely calibrated. Just spraying WD-40 in there might get it moving smoothly again but who can say if its reading accurately.

A final way to check (my prefered) if it’s the cluster is to get another cluster from a wrecker (if you get a budget model cluster they will probably give it to you). Plug that in and take the car for a drive, if the speedo works fine its your old speedo, you can probably put this speedo into your old cluster. If its still jumping around then it’s the cable or gearbox. I am pretty sure all unos have the same final drive ratios so all uno speedos will work in all unos.

 

[tonyfurnell]

Fairly old thread I know, but I've been meaning to sort out the bounce in my speedo for a while -- in fact I've tried a couple of times but haven't been able to pull the cable out from its sheath!

Well either way, the goalposts have shifted now -- the speedometer stopped working completely on the way home the other day, so now I've no speed gauge (and no miles on the clock either I suppose)! Having popped out the clocks unit and unclipped the cable, when driving the car forwards and keeping my thumb on the cable it didn't appear to turn, although it was greased up so it might have just been too difficult to feel the rotation. Again, I tried removing the cable to give it a proper cleanup and grease, but as before it will only come out about an inch, with fairly spongy motion as if it's held fast at/near the other end.

Should the cable come out of its sheath easily when pulled? I don't know if this means there's a kink in it somewhere, or what....

I've taken the other end off the gearbox, but can't actually see the opposite end of the cable inside (should it be as visible as at the clocks end? This might be why the speedo doesn't register...?). And once it was off the gearbox there was still no change in how much could be pulled out from the cab end...

Any advice? At least the MOT was a couple of months back, so it shouldn't be too detectable for a while, but I do actually prefer to drive a legal car (80% of drivers do )

 

[kasedie]

My cable pulls freely but it seems a part is broken in the gear box. Does the end that goes into the gearbox have any variation at the tip or any special way to fit it in? it worked fine for a few weeks but now i cant screw it on as it doesnt seem to catch and just pops back off