In order to replace the Vehicle Speed Sensor (VSS) on the zf s6-650 manual transmission, raise and support the vehicle. For the 6.6l engine, the vss electrical connector need to be removed, and for the 8.1l engine, the vss electrical connector need to be removed. Take out the vss bolt, sensor, and seal out. Apply a dab of transmission fluid on a fresh o-ring seal then fit the vss and bolt and tighten the bolt to 10 nm (89 inch lbs.). For the 8.1l, attach the vss electrical connector, and for the 6.6l, attach the vss electrical connector. Lastly, lower the vehicle and check the level of the transmission fluid, making sure it gets filled.