Yesterday I changed my old speedo ( car was going "25mph" standing still) with used Speedo from Turbo dash pod I got on eBay.Any how I followed "Logans" instructions & was able to accurately reset the "new" speedo to 158,285-exactly like the old broken speedo ! I find it helpful to use a small amount of masking tape applied over the reading on the speedo face to keep the reading from changing as you work. Even with this it was tricky. But it worked to a "T" ! Also installed Tach & smaller clock. Now I know how those lowlife used car dealers re-Set the Mileage !