My speedo needle starts bouncing every now and again when I'm in very slow stop-start traffic. I'm assuming there's a feed from the gearbox somewhere, but where? And could it be down to the speedo conversion as mine's an import? My speedo clock goes up to 180mph or whatever it is and it was imported from new, so the odo reads in miles as well. How does the convertor work?

 

What year is the car? I ask as later imports have the digital odometer and I think the conversion thing is handled differently (not completely sure though)

I had this now and then on my MY94 WRX Wagon. I needed a new speedo cable (one that runs from speedo to the little convertor box that is used to change it from kph to mph) and we replaced the speedo convertor box at the same time, and all was well.

If I recall the mechanic said that the cables were prone to binding, especially when you're using the convertor box, so it could be that.

As for how the convertor works, it's just a little box which has gearwheels of a specific size that changes the speed the cable will rotate at.

 

definately speedo cable, had this problem intermittently myself,

sorted it by pulling the core out from gearbox end of cable & check for damage , I "smoothed" off a couple of high points in the hex section core with a dremel , regreased the cable ( used dry film lube cause its cleaner )
shoved it back in & hey presto sorted.

hope yours is the same, but at worst all it should need is a new cable ( core )

SS

 

It's a digital odometer (98 WRX). Whereabouts does it go into the gearbox? What I mean is should I get at it by taking the intercooler off, or by crawling underneath like where the neutral switch etc is?

 

Yours will be different then to the above, no cable?
Its possible that you have a fault with the speedo sensor which is in the speedo clock.

The part that goes to the gearbox looks like this:

http://www.main.experiencetherave.co...ocablebase.jpg

Bear in mind the picture above is for a cable operated system.
I guess the digital type will be similar but with wires. You can get to this part from underneath the drivers side (its just by the dipstick for the gearbox).

I have read on Nasioc that the speedo sensor can be replace (the one in the speedo clocks) So might be worth a try at the dealers.


Ticky

 

So I'll have to get the clocks out I reckon. Thanks for the tip

 

Well thats if your sure it is the speedo sensor in the clock thats faulty?
Or the part in the gearbox?

Does it a check light (fault finding) or if there was another way of testing it?

Here is the thread from Nasioc.

http://forums.nasioc.com/forums/show...=speedo+sensor

 

Ah that's a point. I'll have a look at the FC Commander's speed readout next time it starts bouncing.