Quivering speedo needle...

[Three Thousand Five]

Not a major problem at all really, more of a niggle... I'm on my third P6 and it's the second one which has this particular affliction, I was just wondering what causes the needle to 'bounce around' even when driving gently at a consistent speed, and is there an easy cure for it....?

Cheers in advance!

Nidge :wink:

 

[Fraserp6]

I believe its something to do with the cable being snagged or slightly caught somewhere, usually where the cable slips into the angle drive at the speedo end.

Fraser

 

[restojon]

I think fraser could be on the money there, it sounds like the cable is partially snagging, twisting in it's sleeve and as it frees up it gives a higher reading on the speedo temporarily and then settles. The only other thing I can think of is that if the speedo is oil damped that the oil has either had it ,leaked out or has been affected by the warmer weather we've had recently, but that is a really long shot and would probably give much more severe symptoms, so stick with the simple stuff first. Give it all a nice clean and lube up and that should see you right.
Best of luck.

 

[quattro]

The speedo head should not be oiled.

If you oil the top of the cable and this oil gets into the head, which is likely, it will make the needle quiver.

I might have made that up :? but I am sure that is what happened to my first ever car, a P6 2000 TC.

Richard

 

[Fraserp6]

I'd be careful how/if you apply oil to the cable, oil has the habit of attracting more dirt, in turn adding to more problems. My money would be on getting the dash out and checking the cable isn't jarred or forced out of line by anything behind the dash.

 

[restojon]

Absolutely right, I should've been more specific. No oil/lube in the speedo head, and don't over oil just a wipe with a greasy/oily rag down the cable I find works well after a thorough clean, if you over oil the rotating action will make the oil find it's way up to the head and clog everything up. Checking alignment of everything is a good thing to do too, no sharp bends or damaged cable outers etc. I've never done a P6 one before but have done plenty of pre war cars and classic motorcycles and with a bit of attention to detail you should be able to cure your niggle.

 

[Dave3066]

Not a major problem at all really, more of a niggle... I'm on my third P6 and it's the second one which has this particular affliction, I was just wondering what causes the needle to 'bounce around' even when driving gently at a consistent speed, and is there an easy cure for it....?

Cheers in advance!

Nidge :wink:

When you say "bounce around" by how much are you talking. My speedo tends to oscillate by about 5ish mph around the indicated speed. You get used to it after a while and I sorta like it as a "feature". Someone mentioned a worn 2nd gear causing this as the speedo drive comes off 2nd.....

My partner's speedo on her modern (8yr old) Fiesta has a tendency to just drop to 0 pretty frequently now and I wouldn't know where to start looking for the cause of that :?

Dave

 

[Demetris]

When you say "bounce around" by how much are you talking. My speedo tends to oscillate by about 5ish mph around the indicated speed. You get used to it after a while and I sorta like it as a "feature". Someone mentioned a worn 2nd gear causing this as the speedo drive comes off 2nd.....

My partner's speedo on her modern (8yr old) Fiesta has a tendency to just drop to 0 pretty frequently now and I wouldn't know where to start looking for the cause of that :?

Dave

Dave, the symptoms you describe seem to come from a generally worn speedo head. Some of the Smiths units could be adjusted for wear, but i have no clue for the certain item.

The speedo drive has nothing to do with the 2nd gear, it is taken from the mainshaft and there could be such problems if the output flange is not as tight as it should be.

Modern speedos are all electronic, no cables to worry about, but plenty of connections, PCBs, sensors, wires etc!

 

[Dave3066]

Modern speedos are all electronic, no cables to worry about, but plenty of connections, PCBs, sensors, wires etc!

Yes that's what I thought :|

Some of the Smiths units could be adjusted for wear

How can I tell if mine is Smiths? And how does the adjustment work?

 

[arthuy]

I have just had my speed overhauled and re-calibrated by Speedy cables. It was around £75 which I thought was great value. It was my P5 speedo but it was over reading and waving badly. So I can recommend them if you go down that route.

Most speedo problems I have dealt with have been cured with a new cable. The inner cable wears a grove in the outer cable. Eventually you will experience the needle flicking.

As the speedo cable is cheap and easy to get to I suggest that first, even if you end up doing the speedo head the cable is money well spent.

Colin

 

[Three Thousand Five]

A belated thanks for all your replies folks, just got home from a thirteen hour shift (train driving and putting out fires, don't do this at home kids!) and have just read them all.... many thanks for the pointers, if you'll pardon the pun!

When my 2000TC used to do it I sort of got used to it, anyway I'll probably have a look at it over the weekend as I intend to use the car a lot over the next two days. Although I've never been keen on digging around behind dashboards it will need sorting out. Dave 3066 asked about the 'bounce'... yes Dave it's about 5mph-ish either way at anything over 30mph. One cosequence of this is that with all the speed cameras and coppers about round these parts, I've backed off the throttle a bit more than usual as the true indicated speed isn't constant in the dial... :wink:

Thanks again, Nidge :wink:

 

[JVY]

My speedo had always quivered by abot 5-10mph at all speeds.
I suspected the cable as the obvious problem and got a NOS item on eBay a while back - just haven't got around to fitting it.
I just got used to it and found that if I go by the top reading, it seems to be accurate.

 

[Demetris]

Some of the Smiths units could be adjusted for wear

How can I tell if mine is Smiths? And how does the adjustment work?

Well, it should say so on the tin!
As i said before, i am not familiar with those speedos, so cannot help you really.
If you feel brave enough, you can take it apart and see what you can find. But first i would do as Colin suggested and check the cable.

Anyway, my car's speedo (strip version though...) at 46,000 Km, fitted new when i bought the car, is perfectly stable with the old cable.

Demetris

 

[Dave3066]

Well, it should say so on the tin!

Very good

But first i would do as Colin suggested and check the cable.

I feel like I've hijacked this thread as my speedo is not that bad so I'm gonna back off and let Three Thousand Five back in (sorry )

Dave

 

[Three Thousand Five]

Well, it should say so on the tin!

Very good

But first i would do as Colin suggested and check the cable.

I feel like I've hijacked this thread as my speedo is not that bad so I'm gonna back off and let Three Thousand Five back in (sorry )

Dave

Hey, no problem Dave, as far as I'm concerned it's what the forum is all about :wink:

I started looking into having another P6 back in October and my first port of call to refresh the grey cells was this 'ere forum, it's a cracking place with lots of good will and very much appreciated it is too. I've already learned a lot about my 3500 over the last week thanks to many of you so a big thanks all round :wink:

All I need to do right now is to pray for the rain to stop so I can get on with a some vital tinkering...!

Nidge