Been driving it today with the speedo cable disconnected and the noise has stopped! So i guess its either the cable itself or maybe the bit in the clocks where the speedo cable goes in? Any thoughts?

which way did you disconect it

id drive it with the cable left on at the gearbox and no clocks connected

which way did you disconect it

id drive it with the cable left on at the gearbox and no clocks connected

i just took the clocks out and disconnected it from the back. Kept all the electrical stuff connected.

so the cable was still on the gearbox?

certainly was, well i didnt disconnect it so i presume it was.