Zx speedo cable

timbo2410 · Post by **timbo2410** » 04 Oct 2010, 15:56

Ok I thought it was just too easy!! I replaced the lights behind the instrument panel on the weekend and all went just fine. The cable wasn't difficult at all and certainly wasn't tight although I did have to slide my hand behind the panel to get it unclipped. All well ... but then this morning (first time I've driven the car since), the speedo is not working at all. I've taken the instrument panel back out and driven around to see if the linkage is turning in the outer sheath ... nope it's not moving at all ..... I'm assuming that I have pulled the cable enough to have pulled it out of the linkage where ever it goes under the bonnet ??? I've looked but can't find where it goes through the firewall. It must be under or behind the brake master cylinders ... anybody know of a cure for getting the cable hooked back up??

evilally · Post by **evilally** » 04 Oct 2010, 16:11

Not familiar with the ZX, but I'm guessing the other end should go into the speedo drive housing on the gearbox?

Old-Guy · Post by **Old-Guy** » 04 Oct 2010, 16:42

The speedo has to be driven from somewhere at the final drive - usually somewhere on the diff housing.

spider · Post by **spider** » 04 Oct 2010, 16:45

If its like the 306 / 205 it will come out underneath / around the brake servo, and go across towards the gearbox at the back where it is usually held in (early models) with a kind of rubber pin.

I would guess either the cable has broken or it has come out, broken is more likely as they don't tend to move that much.

Much rarer is the scroll that drives it has gone for a walk up the shaft (fortunately this is quite rare, which is just as well as its not nice to fix)

timbo2410 · Post by **timbo2410** » 04 Oct 2010, 17:12

Bugger bugger bugger .... is it easy to get to from the engine bay or is it a hoist job? Surely there can't be much wrong with it I knew about how tight the speedo cable was and I didn't yank anything ..... If I can access from the top then I might be in with a chance .. if not then it's back to the mechanic

spider · Post by **spider** » 04 Oct 2010, 17:51

It's easy to do, its behind battery / airbox area. You should be able to see it to be honest.

Apart from the battery leads, the only large cables in that area are the clutch cable and the speedo cable

It is easier to see it from underneath but you can do it from above.

, its just a bit more fiddling from above (but if you take either battery / airbox out so you can see, you can do it from above without any real problem) , the only difficult thing is putting the damn rubber pin back in again.

Take a torch and have a look behind battery / airbox area. You`ll see it. They are (were) off white in colour but probably covered in crud so maybe blackish now.

I would get a pic of my 205 (to give a general idea) but my camera has decided to take a holiday (again)

timbo2410 · Post by **timbo2410** » 04 Oct 2010, 18:35

Ok, I'll dig up a torch and have a quick look ..... man I just don't want to be spending any more money on it .... thanks for the help so far

timbo2410 · Post by **timbo2410** » 04 Oct 2010, 21:02

Man I can't see anything that looks remotely like what your saying ... although I haven't removed the air cleaner and the battery is well out of the way so I won't need to remove that. So does the cable go into the front part of the engine? I would have thought it would go in between the rear of the engine and the firewall? But then I know bugger all .... I'll have another poke around during daylight when I can see a bit better

spider · Post by **spider** » 04 Oct 2010, 21:27

I found two pics (not mine!) that might help

See the white part at the lower left hand side with that bolt in it ? , that's where it goes. Just above the hole where the driveshaft fits.

Note: you do NOT need to remove that bolt. Just pointing it out for clarity.

Different pic, see the white (well, it was) part again (top left this time) , this pic is a bit easier on the eye (although not as clear) as its the correct way around, if that makes sense.

It is quite low down at the back of the box though as you see on these pics (hence me saying its easier to 'see' from underneath) but its quite possible to remove / refit from above, the rubber pin is the annoying part to be honest.

uncle buck · Post by **uncle buck** » 04 Oct 2010, 21:49

Hi,
Assuming your car is a RHD the speedo cable comes out of the back of the clocks then turns & goes along behind the dash then turns again & comes out of the bulkhead then connects to the gearbox.
The speedo cable is a 2 part cable, the joint is a screw joint that is situated just before the cable goes into the bulk head.

Sounds like you may have pulled the inner cable out of the drive at either the gear box end or the joint if that is possible...can't remember how the cable is formed as its a good few years since I worked on mine.

Because of the turns in the cable on RHD cars the inner cable rubs on the outer cable & this causes the speedo needle to jump about a bit at lower speeds. Renewing the full cable will cure the jumping but it won't last for long.
On LHD cars the route of the cable is a nice smooth run from the back of the clocks straight out to the gear box connection.

timbo2410 · Post by **timbo2410** » 05 Oct 2010, 15:22

aha I see exactly what your on about ... a picture is worth a thousand words

.... So should I start with taking it off at this junction or should I take it off at the screw joint first to see if there is a problem? Maybe it would be easier to just buy a new one and fit it .... knowing the way things go it'll cost hundreds ......

spider · Post by **spider** » 05 Oct 2010, 15:35

If it has the screw joint look at that first. I had completely forgotten some have these

Post by **RichardW** » 05 Oct 2010, 21:24

Fitting the upper part of the cable requires removal of the dash board.... hope the bottom part is a goner or you've just pulled it out

timbo2410 · Post by **timbo2410** » 06 Oct 2010, 16:09

When you say "dashboard" I hope you don't mean the whole thing !! Or do you mean the instrument panel that I removed to replace the lights?

Can somebody tell me if the "inner" white drive core for the speedo goes the full length of the sheath ie from the engine to gauge ... I assume that it is ... I was thinking that if I grip the speedo end with some needle nosed pliers and gently twisted and pushed at the same time, it might slot back in to the socket under the bonnet ... get what I mean ??

uncle buck · Post by **uncle buck** » 06 Oct 2010, 21:17

Yes he means the whole dashboard.

The cable is in 2 parts so there is a joint. The gearbox part of the cable has 2 male ends on the inner cable. So the upper part of the cable that goes from the join to the clocks must have a female end on the inner cable at the joint.

Find the joint in the cable & check the female connection is in place.