Speed sensor possisioning

[Bulldog Bri]

I need to fit on a speed sensor for the new speedo. My problem is I'm not sure how and quiet where to put it. It says to place 2mm from a bolt on the prop. Now question is as I've a type 9 gearbox the only bolts on the prop are at the rear axle diff' end and that will no doubt be moving up and down with suspension travel, this gives 2 questions, 1. will the differing cause a problem? 2. which way around should I position the sensor?

Rough diagram

The problem with position 1 is that the flanges of the prop can also come into contact with the sensor as the prop rotates if moves up and down.
The problem with position 2 is that the gap will be constantly changing as the moves (not a constant 2mm gap as required)

It could be fitted to the side of the prop but will up and down movement still cause an issue with the gap?

[Grin-a-lot]

I've done position 2 and it works fine, unless there's a passenger when the gap between bolt and sender becomes too big! I've wound the sender in as far as it'll go but any further and it'll hit the bolts when I'm pushing the car with no weight in it.

I'm looking at sandwiching some sheet metal between a diff housing bolt and the diff housing so that the sender will move in tandem with the diff so the gap won't increase with passengers.

On the plus side it means she can't watch the speedo and tut at me!

[Hairy Santa]

are there any bolts close by on the axle to mount a bracket so as it all moves together ?

[Bulldog Bri]

Not that I can see, prob' have to drill and tap the casting and it would have to be on top as underneath I'd be worried about knocking the sensor.

[Hairy Santa]

How about from the ring of bolts holding the diff in

[Bulldog Bri]

can't see any


Or do you mean from the back cover plate??

[Iancider]

Brian,

If you can it is far better t take the wheel rotation from the front wheels.  Mount a bracket on the hub and the wire goes along the wishbone.  Sense the hub bolt-heads passing within 2mm of the sensor using a really riging bracket so that there is no risk of vibration and collision.  it is also imume to wheel-spind on accelleration but might under-read during a sustained skid!

Ian

[peterw]

Got mine on the inner flange of the half shaft right next to the diff, that way if I change the diff ratio I don't have to recalibrate the speedo. Operated from two small magnets araldited to the flange

[Bulldog Bri]

Guessing you have a Sierra diff' then. I've got a live axle so no half shafts to play with. Thanks anyway. 

[Hairy Santa]

can't see any


Or do you mean from the back cover plate??

Sorry mate thought you had a different axle, how about a clamp or 2  (like jubilee clip ) around the nose of the axle holding a small bracket for the sensor, you may be able to drill small hole in the ribbing as a back securing point   

['The Gaffer']

I too have used front wheel hub bolts with sensor on a bracket, never had any problems.

[Bulldog Bri]

Thanks guys , I've had a look with Ian at my front hubs and it looks like that where I'm going to give it a try as well.. Anyone got a photo of how theirs is attached would be great.

[Quarrycars]

Is there a sensor available that will fit into the old speedo drive in the gear box?

['The Gaffer']

Is there a sensor available that will fit into the old speedo drive in the gear box?

Ive never seen one, the electronic ones are usually small non mechanical devices that pick up movement from rotating objects like hub bolts. Interesting thought though.

[Quarrycars]

I know with the Toyota box I used on the Furore the later versions had an electronic sensor that was interchangeable with the mechanical one, aftermarket ones where also available.  The other thought is that older Range Rovers had a sender that was driven with a short speedo cable, don't know if that would be adaptable.

[damouk]

I believe some of the ford speed sensors are electro mechanical devices, but will need an adapter to fit the type 9 box

[benchmark51]

If you have cortina hubs on the front, as I have, then there is a perfect place for it above the backplate
bolt hole.

['The Gaffer']

I know with the Toyota box I used on the Furore the later versions had an electronic sensor that was interchangeable with the mechanical one, aftermarket ones where also available.

I stand to be corrected, said the man in the orthopaedic shoes .