Firstly, hello from the UK

The missus has a 98 306 diesel Peugeot, and the speedo is playing up.

When you set off at any speed, it shoots up to the end of the dial and sits there. Sometimes it drops back to read about 120mph, and then 'ticks' downwards to 0 when you switch the ignition off.

Peugeot main dealer has said the dashboard needs replacing *Cough********!

Anybody got any ideas what it could be, before I start stripping the dash out?

It the 306 speedo on this model electronic or cable driven? Maybe a problem that could be fixed by replacing the speedo with one from a scrap car? Or the connection from the final drive to the speedo?

Any help in avoiding a huge garage bill would be greatly appreciated.