As far as I know you can only by ones made by VDO. There are no other options.
With some early boxes the box side is a bit too big so you need to add a bit or girth to the transducer.
Maybe this is the one I should be using? Looks much smaller...
FOR LAND ROVER DEFENDEROVERY Mk1 300 Tdi 1989-98 GEARBOX SPEEDO SPEED SENSOR | eBay
Just read this thread. I've often thought a GPS speed sensor would be the way to go.
What would even be better is if you could fail back to the gearbox if the GPS signal was lost in a tunnel, etc. And the ability to adjust the output from the gearbox unit.
Rich
The VDO electronic ones are programmable, for example when you change to larger or smaller tires.
I did this conversion in my County. The VDO speedo is easy to program for whatever setup you have and very accurate.
So I've collected all the pieces to do this conversion but on attempting to fit the sensor it seems I've somehow order the wrong part. I order a YBE100530 from eBay which looks like this:
Attachment 146770
A bit of googling suggests it should have the alloy collar like this:
Attachment 146771
Does anyone know if the Land Rover part number- i.e. YBE100530 - should include the collar ? That is, is the part I bought actually just the VDO component rather than actually a (complete) YBE100530? Obviously, if I was replacing a dead sensor on a TD5 I could just remove the nut and fit the collar from the existing sensor...
Having just done an electronic speedo conversion on my County/LT95 - I can confirm the above info is correct if using the YBE100540 sender (from D1 etc). Connect the sender to pins 7&8 on the speedo.
NB - seems there are 2 different square drives in the transfer case drive gears. The original one on my county had a slightly larger size so the sender shaft was a bit sloppy.
I've since read on a couple of UK sites that its a known issue. Some people fitted a square brass sleeve to overcome it.
I ended up using the matching drive gear from the disco that donated the sender. Disco one is a different colour gear and no. of teeth, but not a drama since the speedo is calibrated to suit anyway.
EDIT: I'd be really interested to confirm if there's a difference in the square shaft size between the 2 senders if someone has a Defender style YBE100530 sender lying around and could measure it.
Steve