I have a 1983 300D and my speedometer is gone wonky! My odometer is not working and my speedo is reading incorrectly. When it reads 30 MPH, I'm actually going 24 MPH! there seems to be a 2 MPH discrepancy for every 10 MPH of speed and this increases exponentially! What can i do about this? I know I'm going to need a speedo. Is it possible that my 300D was made for a 85 MPH speedo instead of a 120 MPH speedo? Thanks. I know that working for the Chrysler Corp, they would have a gear reduction mechanism to correct this error, but how about Benz? I'm getting conflicting responses from shops around here!