We should mention that the differential gear oil needs to be changed every 30,000 miles as part of normal service. If you are due for a change, a good suggestion is Mobil 1 Synthetic gear oil - good stuff.
I just joined AAA Plus. 100 mile towing included. My workplace is about 65 miles from home, so I can get AAA to tow me home anywhere along the route.
http://www.aaa.com/
Ken300D