E34 Speedo Problem

Hi, the needle on the speedo in my E34, starts off at below 0mph, so when it says I am doing 20mph, then I am probably doing about 30mph.
It is a pain not accurately knowing what speed your doing, as plod doesn't take a faulty speedo as an excuse.
So any ideas of how to fix it? (other than buying a new instrument cluster)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.