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
Not sure
Hi Dieter, not sure on that one since I have never done that conversion. Call Overseas Speedometer (Google them) and ask them. They might even be able to recalibrate you SD speedo to the lower ratio. Keent
how did it differ
I think a low 2.xx gear in my 86 300SDL is too high? what gear ratio did you SD have and what gear did the 420 have that you swapped in? How much did the RMPs jump at speed (hiway in top gear) compared too stock? Did it bolt right in place of stock? I know there are alot of ?? in this post but I would like some of your wisdom on this matter so i know wheather I'd like to do it someday..... thanks for any info NOAH B.