Erratic Speedo

[Multiphonikks]

Hi folks

Hebe has been the perfect lady since I got her and today we covered a total of about 100 miles.
On the way back home, she decided at about 70 mph that her speedo should play tricks on me.

And now...

Her speedo is anything but accurate. It jumps all OVER the place.


Any suggestions in how I may fix this? Several tips suggest either a stuck cable, or similar.

I'm hoping to take the speedo out tomorrow and have a look, but at the momemnt I have no way of getting underneath Hebe!

Nikki

[MrA.Series]

Could be the cable...
http://www.morrisminoroc.co.uk/index.ph ... pic&t=3848 for more on this.

Or it could be the speedo itself giving up the goast.

[Multiphonikks]

Could be the cable...
http://www.morrisminoroc.co.uk/index.ph ... pic&t=3848 for more on this.

Or it could be the speedo itself giving up the goast.

This sounds about right.

Hebe's previous owner did under 1800 miles in her last year.

Up till yesterday she did have a shudder at 40 mph, before settling back again at about 45 mph. Her previous owner having not driven her much above 50 mph...

Could I lubricate the cable? Or pop along to my garage???

Nikki

[Matt]

well how big is the wobble....

[rayofleamington]

Be careful with a speedo that suddenly gets erratic! The speedo rear bearing can pack up if it runs dry (especially If the cable was never lubricated - oild from the cable normally spreads a bit to the speedo).
I had one that started to twitch out of the blue and it lasted a week before the speedo seized and sheared the cable. Therefore if the cable is dry - also consider a drop of oil into the back of the speedo too.
Cable waiver is unlikely to happen overnight or whilst driving on the motorway - either you had it to start with, or you don't. Therefore if there was a step change as you describe it'll probably be something else

[Multiphonikks]

Hmmmm.

I'm going to take the speedo out this morning and have a look. I'm hoping that I can put some oil in there and at least keep the speedo happy till I get a new cable ordered. (If that's the problem)

As to accuracy pre-yesterday, she had a few points on her dial where she behaved quite erratically, and also tended to bounce around a bit when going over bouncy roads... Given the fact that she wasn't cleaned very much by the looks of it, and the fact that she didn't seem to have been driven much, I'm guessing the cable. At least I HOPE it's the cable. How much would I be looking at to replace it???

[Multiphonikks]

To add to the post....

I took the speedo out (who said the self retaining screws were bl**dy self retaining?! - they've disappeared somewhere by the glove box!)

There was a noticable anoumt of grease by the speedo itself, but the cable *did* feel quite tight in places. I've lubricated it again just to make doubly sure (there were moments of more resistance before which I've now fixed) However, test drove Hebe and she's still playing her tricks. I have a suspision it's the speedo rather than the cable, but a few questions:

a) how much resistance is acceptable from the cable? If I replace the cable, do I need to replace the outer too? - I don't currently have accsess to the box as I don't have any kind ramp/lift.

b) if I make a trip to the local scrapyard and salvage another speedo, what are the legal implications of switching them round? (as far as legal milage goes)? - and presumably I need to make sure I get another 1098 speedo right?

Cheers!

Nikki

[Willie]

Re the cable, I presume that you know that you twist the inner
cable and withdraw it completely from the outer once you have
undone it from the speedo? If you didn't do this it is worth doing
so that 1. you can inspect it for frayed strands/kinks etc and
2. you can completely clean it of old lubricant and then re-oil.
after re insertion into the outer cable twist it until you feel it
go into its housing in the gearbox end then withdraw it about
four inches and wipe excess oil off. NO the speedo fixing screws
are not self retaining and never have been! I fitted a second
hand speedo years ago and found it quite easy to turn the mileage
to the exact reading on the old one. YES you must get a speedo
from the same type of vehicle due to gearing differences and if
you fit the wrong type then the FUEL GAUGE will not work as well
as the wrong speed being shown.

[Multiphonikks]

Damn - it appears my speedo works very accurately, but 30 mph faster than it actually is!!!

I think I've broken the thing. - It's a case of waiting to see what happens. I've won an auction on ebay for a new speedo, and I'm probably going to visit the local scrapyard too...

[Multiphonikks]

Just an update.

The speedo has (after my father-in-law's advice to put the smallest bit of vaselene in the back of the speedo where the drive shaft attaches) settled down. She's now reporting pretty accurate speeds above 20 mph. The action isn't as quick as I'd like recording decelleration - (of course that'll be the vaselene - I didn't have any white graphite) a delay of about .3 of a second seems to be in order at the moment. All I can say is it's nice to have a speedometer which is a) accurate and b) doesn't go haywire.

I'm hoping it settles back down to a sensible reporting of the speed over the next few days (I was told a hundred miles or so should help it self regulate)

Nikki

[Kevin]

Well having a wobbly speedo like yours Nikki I changed mine for another over the weekend after trying all the cable tricks etc and it only reduced the needle bounce from 30mph to 25mph, so yesterday the replacement went clonk and jammed at 10mph, well on removal the cable was intact although now appears stuck in the outer but turns as normal when driven but the speedo appears to have seized up, so on went another spare and all appears OK, I just hope there is not a problem with the cable as well but the run to Donnington will reveal if there are any problems.

[turbominor]

make sure that the inner cable is not too long as if it is forced into the speed when you screw it on as it will make the speedo erratic or read wrong as it pushes the mechnaism