Differential swap
 

Howdy guys, I have a '82 300 D that has the low gear ratio diff. I want to put the diff from a '85 TD with the 2.83 ratio..anyone ever do this?..supposed to be a easy swap .. what needs to be changed for the speedo to work properly?..thanks for any replies

gauge cluster

because of the speedo being specific to diff. ratio, many just do the math for MPH per 1000rpm of tack with the new gears and use the tack as a speedo guide...[ if you have a tach]

I have done this and you just get used to it....

Google has some nice RPM/Ratio speed calculators that are number plug-ins --- do a search...