Mercedes Benz repair: 300D Speedometer Cable, speedometer cable, auto help

Question
I recently got a 1980 MB 300D.  At the end of a long road-trip (approx. 1400mi), the Speedometer quit working. I looked up Speedometer cables and found that I can by one for under $60. I'm no stranger to car repair, just to the Benz. Can someone give me the skinny on Troubleshooting/ Replacement of this part?

Answer
remove the cable from where it goes into the transmission and spin it with a drill see if the speedo works. If it does not work them you must see if the cable is really broken. Because there are other things that could be wrong other than the cable.
Let me know
Ralph
Miami Auto Help Inc