Speedo Sensor - where is it?

[Griff Boy]

Hi Guys,

I have a problem on my 1996 Griffith 500, the speedo and odometer have both stopped working, and I assume its the speed sensor and I ordered one from Steve heath complete with diagnostic thingy and tried to fit it yesterday, but I can find the sensor!

I am right in thinking its on the rear differential? according to the instructions I should be looking for a cog type wheel which the sensor sits close by, but my car has nothing like this anywhere near the diff. Is it different for my model / year or am I just being thick. (polite answers only please!)

Any help / pictures would be great.

cheers
Ian

[V8 GRF]

There was a thread with pictures about the sensor on here a month or so ago, have you tried searching?

[HRG.]

It's not a cog as such, it's more like a tuna can with regular cutouts

If you look above the diff at the end of the prop shaft you'll find the sensor. IIRC it's the only wire up there so you should be able to follow it if you can find it.

[Griff Boy]

Thanks guys,

Is it best to get access to this from underneath or via the offside wheel arch area?

I tried the "from underneath" approach yesterday and couldn't see anything. I think I have the latest diff, definetely the t5 gearbox anyway.

Does anyone know if steve heaths sensor can be fitted by itself, or do I have to take the dash apart? I realise the diagnostic option is better, but would the sensor work without it fitted?

Cheers
ian

[HRG.]

You can see the trigger wheel in this pic



It's the castellated object visible behind the front diff bush in this pic. Sensor lives in the 12 o'clock position immediately above it.

[steve-V8s]

On later cars it is on the Diff output shaft, driver side.

[Griff Boy]

Cheers hrg, that's exactly what I was looking for, and it explains why I couldn't see it from underneath. I'll take the rear wheel off tommorow!

Do you know anything about the steve Heath sensor kit? Can I just swap the sensor and expect it to work?

Will try the cleaning / distance check first in case it's something simple, there does appear to be done witness marks on the castlated bit when I looked from underneath?

Cheers
ian

[HRG.]

I believe it's a direct replacement subject to wiring it up. The originals need a very small gap but the SH ones can run with quite a bit more.

When I refitted mine I tywrapped a square to the chassis and used it to bend the tangs till they were all square again They're very malleable as long as you're sensible about it.

[Del 203]

Griff Boy said:

Cheers hrg, that's exactly what I was looking for, and it explains why I couldn't see it from underneath. I'll take the rear wheel off tommorow!

Do you know anything about the steve Heath sensor kit? Can I just swap the sensor and expect it to work?

Will try the cleaning / distance check first in case it's something simple, there does appear to be done witness marks on the castlated bit when I looked from underneath?

Cheers
ian

Just so you know your taking advice from this man

[HRG.]

There's much worse than that

[shpub]

Griff Boy said:

Does anyone know if steve heaths sensor can be fitted by itself, or do I have to take the dash apart? I realise the diagnostic option is better, but would the sensor work without it fitted?

The sensor I use has a totally different interface which needs the box to convert the electrical signals. Having had to do an interface to get it to work with the speedo, I decided that it would be a big advantage to build in some diagnostics as the original setup is notoriously difficult to test and diagnose. The sensor on its own will not work. Once installed, setting up the sensor and testing the speedo etc is an absolute breeze. The sensor gap is around 1mm which means that any run out on the trigger wheel or dirt will not destroy the sensor which is often the case.

It's a little more involved to fit but works a lot better and is less likely to fail.

I'll have a demo setup at the Growl on Saturday.