Fitting New Speedo Sensor

[Guest Daniel N Sharman]

Hi all

 

I have just taken delivery of my new speedo sensor which needs to be mounted so it sees the bolt heads of the props haft joint rotating past it

 

My s7 is sierra based, I'm wondering how others have mounted the sensor and where?

 

I understand the principle but any clever or simple solutions would be greatly appreciated

 

Thanks in advance

 

Dan

[Guest peter2b2002]

i use 4 magnets stuck on a half shaft ,pick up bolted onto the dif, I have tried mounting near the prop bolts but i think the gear box mount is a bit soft so the signal/pick up was a bit hit /miss

peter2b

[Guest Daniel N Sharman]

Thanks peter

How did you bolt the sensor to the diff and how did you stick the magnets to the shaft?

Cheers

Dan

[Guest Jameslark]

I made a bracket up secured to underside bodywork and then glued the magnet to the top of the diff flange with superglue ( the original not rapid set) just made sure I fixed it whilst top dead centre and then left to cure for 24 hours. Not come off yet. Just make sure you giver the area where the magnet goes gets a good sanding back to bright metal

[Guest Daniel N Sharman]

Ok great thanks, my sensor has not come with any magnets and senses bolt heads apparently so I guess it's distance related and not magnetic?.

 

[sj-bradley]

Is it 3 wire ?

 

I.e +12 gnd and signal. If so, then it generates its own magnetic field and only requires some steel to pass by closely to induce a signal in the sensor. Magnets not required.

 

That's the principle on my smiths sensor. Just point it at the bolts heads on the diff. It may also flash as the bolts pass by the sensor so you can see it working.

 

Simon.

[Guest Daniel N Sharman]

Simon, yes it's 3 wire and it does have an LED indicator, I'm gonna get out there tomorrow and see where I can mount it I think mounting it to the underneath body on a bracket sounds the best plan for me as I'm not sure about undoing diff bolts to get it on!

Cheers for the help

Dan

[cb750]

Caerbont who are supplying my 3 wire sensor got Smiths telemetrix gauges have the instructions on their website. The guy there said the sensor head needs to be about 1mm from the flats on the bolts and light will flash when it senses the heads, also the 4 pulses per rev should be enough for speedo accuracy.

Rob

[Guest mower man]

A lot depends on sensitivity my ETB speedo works fine with 2 magnets bonded to the prop [ even works at half speed if one becomes detached ] just make sure that there is no wander on the prop mowerman

[Guest davidimurray]

I used one of these - http://www.digital-speedos.co.uk/cable-drive-converter-for-ford-type-9--mt-75-gearbox-157-p.asp

 

Was a lot cheaper though when I bought it !

[sj-bradley]

Hi,

 

I made up a bracket that bridged the tunnel over the top of the prop and when the sensor was mounted it just pointed right at the diff bolts. No magnets were required to be glued on anywhere, just the mere passing of the diff bolt heads is enough for this sensor.

 

I take it from the sounds, it's a Smiths sensor?

 

Simon.

[niduncan]

Have a look at this old post http://www.rhocar.or...topic=33357&hl= there is a picture of the way I did it.

 

Nigel.

[churchy]

Hi, I fitted smith flight dials which had the same sensor but the only problem is if where you are sensing moves at all under load from the. engine then it will not sense or worse take out the sensor, which happened to me so I fitted the same unit as David Murray showed that fits onto the old cable drive point from the gearbox and have never looked back the speedo reading is accurate and don't have to worry about making a bracket or catching the sensor, hope this helps, good luck andy

[Guest Daniel N Sharman]

Great advice from everybody, I'm getting the car on axle stands today for some other bits so will get under and see what's what....