Automatic transmission cars have the neutral safety switch on the firewall, connected to to the transmission with a cable. There is a ball socket (Kugelpfanne) on the firewall end of the cable. According to Gernold, the correct Kugelpfanne was not available for many years, and a plastic substitute was used.
Well, I am happy to report that Mercedes has brought the correct Kugelpfanne back. It even has the two little holes on the sides to take the special tool used to secure it while tightening the nut on the on the bottom.
If you have a Kugelpfanne, take care of it. A replacement lists for $104.98. PN is 127 300 00 86.
