Dear All,

I have searched and searched through all of the old threads and I can't find anything that shows how to identify which differential is installed on my 1981 w123 300D:-

I am looking for an easy way to do this - without removing it from the vehicle!

{Background information:- I've owned the car for 2 months and it is my first Mercedes. I live in the Netherlands where there are lots of information boards that tell you how fast you are driving (Radar). Every time I go past these things they tell me I am traveling about 7% slower than the speed limit. I've checked the back tires and they are not the recommended size. I have 195/65 R14 fitted where I believe they should be 195/70 R14 => calculations of the corresponding circumferences for these tires suggest that the ones fitted are about 3% smaller - but that doesn't quite match up with the difference in speed that I am seeing - SO I GUESS the differential is not the correct one for the car...?}

Any help will be greatly appreciated