Intermittent speedo fault

[StarCruiser]

Have a search. I’m not sure if the encoder on the gearbox is different but I suspect not as that would make your speedo wrong. I would be tempted to post for a second hand unit as others have done and see if what you get works. I think the speedo unit is less challenging to find correct than the complete gauge cluster.

 

[PeterLC]

Hi Starcruiser,
I have no idea whether this is still relevant for you but here is something you can do before you start spending :
(I have a LHD)
behind the glove box, locate IG1. Pin 18 carries the speedo sensor signal, the wire is coloured red/orange. Connect a volt meter or better even a scope to it. Jack up a rear wheel (make sure all diffs are open) and rotate it. You should see the pulses from the sensor, they have a 50% duty cycle and the levels are close to 0V and 12V. In normal operation you can expect 5,7 pulses per revolution so you will see only half that as you have only one wheel rotating. If you have this signal, look downstream towards the instrument, else look upstream towards the sensor.
If you use a scope, you can rotate the wheel using your engine (immobilize the car!). If you are lucky and Murphy's law doesn't apply to you, your speedo will fail during the test.