Speedometer not working.

[skendo]

Hi all, I'm having an intermittant problem with the speedo in my 2005 hilux. Somtime it works and sometimes it doesn't work at all. Also it under reads by about 8KMH. If my GPS reads 68KMH my speedo reads 60 KMH........yes I've had a few speeding fines lately. Now no dash lights at all.
Odometer still works as does Tachometer. Albany Toyota has had a look but after $400 dollars worth of work it is still not fixed. I'm sourcing a new/2nd hand instrument cluster but am wondering if anyone else has experienced the same problem and what they may have done to fix it.
It is an ex mining vehicle too so I'm not disilusioned that it has probably had some hard driving and possibly some dodgy quick fixes in its life.

Any advice or similar stories would be much appreciated.

[cizzink11]

Your tires could throw the speedo out. What size are they?