speedo help

[JonyTVR]

something that I knew needing sorting when I bought the chim is that the speedo isn't working.

now I understand there are 2 sensors? where are these exactly and is there a way you can test them? one was only replaced about a year ago so I'm wondering if there could be a bad connection somewhere also.

any help appreciated guys

[.Mark]

The usual culprit is the sensor on top if the diff. It has an air gap that somehow magically senses road speed. A bit tricky to get at, blasting some air through worked for me for a short while but it was only temporary.

Not sure where the other sensor is though.

[JonyTVR]

cheers Ill check that out, My 'bible' has just arrived in the post today so will be having a read through that tonight before the weekend!

[TJC46]

Heres a pic of the speed sensor on the diff. I dont know if this set up is applicable to earlier cars, but mine is a 1996 model.

The sensor is in the middle of the pic. You can see the "teeth" on the diff output shaft, check in your bible there has to be a precise measured gap between the sensor and the "teeth". I set mine to the correct gap but it still didnt work. It was a case of trial and error, i.e. trying the gap bigger or smaller till it actually started to work, a bit of a pain in the ae but i actually tested it each time i made an adjustment, by starting it and putting it in gear while it was still on the axle stands. Be very careful if you test it this way......wouldnt want your pride and joy jumping off the stands and goin thru the garage wall!...

[JonyTVR]

you sir are a legend! I know exactly what to look for now. only thing is, is there a way to check if the sensor is duff or not? I dont wanna spend an hour trying to get the gap right if the sensor is knackard.

cheers

Jon

[Excitedoldgeezer]

I have just had my speedo fixed, it was acting like a revometer after 50mph, turns out that the bush had gone on the diff and that the whole diff was vibrating widely at high speeds, and had knocked the sensor out of alignment, so the sensor may be fine and the bush could be gone?

[JonyTVR]

Excitedoldgeezer said:

I have just had my speedo fixed, it was acting like a revometer after 50mph, turns out that the bush had gone on the diff and that the whole diff was vibrating widely at high speeds, and had knocked the sensor out of alignment, so the sensor may be fine and the bush could be gone?

cheers will try that, mine just doesn't work full stop, the mileage counter also doesn't move so something is not connecting somewhere.