Bouncy Speedo

Post by **peatbrown** » Fri Jul 30, 2004 9:35 am

Hi Guys,

Just bought myself a four door saloon to add to the collection, although I can't be too sure how long she (the car, not the wife) will be staying!

I have a problem with the speedo needle bouncing through a range of about 40mph on the clock. I have checked the fitting on the back and it is screwed in fully and tight - could it be the other end at the gearbox?

Also the milometre isn't working, could the two things be linked in someway...?

I think that's about it - oh no, the petrol gauge works intemitently, I have followed the process for checking it as printed in the workshop manual but to no avail. Sometimes it works more often than not it doesn't. Problem is it got a bit low the other day and started dragging the muck form the bottoom of the tank with disasterous results. Anyway, my wife thought the AA man was lovely.....

Regards
Dave

Post by **Kevin** » Fri Jul 30, 2004 12:16 pm

Sometimes the bounce can be reduced by disconnecting at the speedo and removing the cable to check there are no kings etc in the cable, if all looks ok clean the cable and lightly lubricate and put back in the outer sheathing and then pull out the 1st few inches and wipe the oil off and reinsert the cable, when I did this with mine it reduced the bounce to about half and in the end I replaced the speedo with another.
You say you checked the petrol guage, I assume you earthed the guage at the tank end 1st to check that a full defection (full) was shown by the guage if so the tank sender unit sounds faulty, what did you do and what were your results.

Post by **Multiphonikks** » Sat Jul 31, 2004 9:02 am

Hi

The other thing which you may want to try is to put some white graphite dust on the end of the speedo where it connects to the cable from the gearbox.

It apparently doesn't affect the speedo resistance, but does lubricate it

Mine did exactly the same some time ago, and I stupidly put WD40 in it... that solved the problem but made the speedo wholy inaccurate!!!

Post by **ColinP** » Sat Jul 31, 2004 10:37 pm

Dave,

One thing you can do easily(!)
Check that the speedo cable makes a smooth curve from the back of the speedo to the gearbox - no sudden changes of direction, not clipped to anything else etc.

I'd pulled the speedo forward, and on replacing it, I had a wobbly speedo needle until I smoothed out the curve.

Colin

Post by **Pyoor_Kate** » Mon Aug 02, 2004 10:32 am

If the milometer is stuck, that could be increasing the 'bounce'. When mine sticks (at x7999.9 miles, it appears*) the needle bounces like mad, but only every 1/10th of a mile. Taking it apart and freeing the mileometer cured mine, more or less. Possibly the speedo cable needs lubricating, or has it got a kink in it? That can give you a wavey speedo.

* fortuantely it unstuck itself this time....