The Reason The Speedo Wobbles.

[Guest BrainFluid]

Pointed out the speedo wobble today to Andrew and he said that its because the magnets at the binical have been next to each other for so long it starts to wobble because they have altered each others polarity a bit.

 

He did say that thats what speedos used to use to work, and mentioned the 205 might not have them.

 

Thought it was worth sharing with you all seen as so many people suffer from this problem and depending on if they can be changed or not it may well be some kind of holy grail.

Edited December 11, 2006 by BrainFluid

[j_turnell 137 3 Cars]

Generally its said that the grease in the cable drys out due to the close proximity with the exhaust manifold, if you replace it it should cure the wobble. A genuine pug one is around £25 and i think there is 3 different lengths, get the longest one.

[Guest BrainFluid]

Yes, but I have also heard that replacing the speedo cables does not last very long before the wobble comes back!

 

Could it be that were throwing away perfectly good speedo cable that may have had their intial little bit of bedding in stretch and are perfectly fine BUT it is the old magnets that are not 'picking up the slack' as it were, and back comes the wobble.

 

See where I'm comming from?

Edited December 11, 2006 by BrainFluid

[j_turnell 137 3 Cars]

This is a possibility, not sure how you'd prove this was the case though, wtihout lots of swapping about.

[Guest BrainFluid]

Well, how long does a replacement speedo cable usually last before the wobble comes back?

 

Anybody fancy a little experiment?

Edited December 11, 2006 by BrainFluid

[Alastairh 47]

Can't remember who it was, but a good 18 months ago, didn't someone on the forum buy a new pug cable and wrapped it in heat wrap etc, but a couple of months still get wobble.

 

Im sure some of the older ones will remember with better memory...

[Guest rick03054]

My speedo didn't wobble at all, but the cable snapped, I replaced it with an old one I had. Now it wobbles .

I have no idea about the magnet thing, but the dried out cable is a definite.

 

What experiment did you have in mind Nate? Other than ripping a speedo apart to see if it even has magnets?

[Rob Thomson 6]

It's 99.9% to do with the cable. As they get old the lubricant dries up, and the increased friction causes the cable to wind up like a spring, and then release. Hard to explain in few words, but basically the gearbox end is being driven at a constant speed but the other end fluctuates. This is most noticable at low speeds.

[mos 1]

hi,

 

i have never come across a speedo wobble on a205 that was not fixed by replacing the speedo cable and or the plastic speedo drive in the top of the gear box and then giving at least 3-4 years of trouble free usage

thats on about 7 cars owned by friend/family as well as my own cars over the last 12 years or so

 

thanks

 

mark

[RichE 0]

Can't remember who it was, but a good 18 months ago, didn't someone on the forum buy a new pug cable and wrapped it in heat wrap etc, but a couple of months still get wobble.

 

Im sure some of the older ones will remember with better memory...

 

That was me. Almost 3 years ago, wow time flies.

1 New speedo cable (About £10/15) and £75/£80 of special race spec heat wrap from demon tweeks.

 

All fitted and wrapped up, it lasted for the entire time I had the car (About 8 months) before it got broken into and trashed, then as I was doing more miles I got a mondeo.

 

But yep, for approx 8 months the speedo needle was as smooth as a babies bottom, no wobble at all.

[M3Evo 0]

Only taken one speedo head apart (to looks at it's workings anyway) and it had a pair of magnets end to end arranged to form an anulus (don't laugh).

 

These were spun by the cable inside a cup that was only very slightly magnetic when touched with a magnet. The cup was connected directly to the speedo needle and had a very very light spring to bring the needle back to zero and of course to stop it just wanging around to full speed the first time you move

[Guest smokinslim]

Another thing maybe worth noting, the plastic bit in the middle (on the end of the cable that plugs into the speedo) wears in time and becomes a bit loose in its socket. I noticed this one time when my speedo was out, that mine was badly worn, and the needle had been jumping quite a bit. I stuck a small blob of blu-tak in the socket on the back of the speedo to give the cable a bit more grip. Sorted out the needle a treat

[Rippthrough 98]

Another thing maybe worth noting, the plastic bit in the middle (on the end of the cable that plugs into the speedo) wears in time and becomes a bit loose in its socket. I noticed this one time when my speedo was out, that mine was badly worn, and the needle had been jumping quite a bit. I stuck a small blob of blu-tak in the socket on the back of the speedo to give the cable a bit more grip. Sorted out the needle a treat

 

Often overlooked that

Filled and reshaped it with a little epoxy on the 405, but blu-tak sounds easier!

 

 

P.S.- I heard if you stop the speedo wobbling completely, the peugeot badges fall off...

[Simes 248 2 Cars]

Can't remember who it was, but a good 18 months ago, didn't someone on the forum buy a new pug cable and wrapped it in heat wrap etc, but a couple of months still get wobble.

 

Im sure some of the older ones will remember with better memory...

 

richE is who did that - spent a fortune.

 

My OE one started wobbling after 2 weeks, about 5 years ago. Apparently I could spend ages trying to route it a bit better but I prefer to work out the speed by taking the mean from the two points!

 

LHD cars don't suffer so much from this as their cable is far shorter and more direct.

[Beastie 1]

Only taken one speedo head apart (to looks at it's workings anyway) and it had a pair of magnets end to end arranged to form an anulus (don't laugh).

 

These were spun by the cable inside a cup that was only very slightly magnetic when touched with a magnet. The cup was connected directly to the speedo needle and had a very very light spring to bring the needle back to zero and of course to stop it just wanging around to full speed the first time you move

 

 

The cup is usually made from aluminium alloy and is often completely non ferrous and therefore not detectably magnetic. The rotation of the aluminium cup causes eddy currents to form inside the magnets which cause them to alter the position of the needle. It's all to do with Edddy Currents in your annulus I'm afraid.

[M3Evo 0]

Interesting, must have been picking something like the spindle up with the magnet I was using or something.

[Guest STEVE'O]

I allways thought the main reason the speedo wobbles is just down to the fact the cars were originally designed as left hand drive for the rest of the world,

And in adapting it to our market the speedo cable has to take a un- natrual route up to our RHD binicles, & over time the cables start to give and weaken.

 

Ive had this problem in most of my 205's and both 106's I've owned

 

Same poxy reason you have to take the dash out on 306's and 106's to change the heater matrix, instead of getting at it from the glove box's like continetal cars!

Not that Im bitter about it

[DaveW 6]

Even my mk1 mondeo has speedo shake!

[Edp 67 3 Cars]

Ah Eddy currents I remember them from college class rooms many years ago.

 

I have replaced the speedo on my Mi and it still wobbles. I'm not sure about this magnet thing as when you go abouve 50 it works fine. I reckon its the speedo drive in the gearbox.

 

[mos 1]

Ah Eddy currents I remember them from college class rooms many years ago.

 

I have replaced the speedo on my Mi and it still wobbles. I'm not sure about this magnet thing as when you go abouve 50 it works fine. I reckon its the speedo drive in the gearbox.

 

 

 

i have always found it to be the speedo drive in the gear box or the cable

never once had a problem with a speedo itself