Kent,
I replaced the rear axle assembly, axles and final drive, of my 1983 300SD with one from a 1991 420SEL. I really like the result with one exception: the speedometer is off (something was wrong when I started passing everybody on the highway at 55 mph). I read somewhere that the problem would be fixed if I repalce the speedometer with one from a 420SEL. Does that make sense? The 420 has a speed sensor in the final drive, the 300SD gets it speed information apparently from somewhere else. Any suggestions would be appreciated.
Thank you
Dieter