Land Rover Repair: speedometer VSS problem?, vehicle speed sensor, throttle position sensor

Question
Hi John,
    Two questions. Where is the speed sensor on my 96 disco?  What would cause my speedometer to behave erratically?  Thanks, you sir are the greatest.
                                           Vince

Answer
Hi Vince,

96 speed sensor is located on the transfer gearbox (LT230T) and is held in place by an allen screw.  

It's possible that the VSS (Vehicle speed sensor) is at fault.  I've had my speedometer go 'wild' but it was due to a TPS (throttle position sensor) failure.  If you engine revs wildly (speedometer would go wild too), it's possible that the TPS is at fault.

IF you simple see the speedometer go 'wild' without engine rev, then you may have a VSS problem.

Regards,
JohnMc