Cummins12V98 wrote:
I highly recommend AMZ/OIL SevereGear 75-110 for towing applications. The pic below is at 65K. I changed to AMZ/OIL at 15K. Most of the miles were towing a combined 27-29K. The ring gear teeth still have machining marks. The fluid came out a golden brown.
Keeping my above post in mind, I changed diff oil in my 07 at about 15kmi to Amsoil 75-90. Changed it again at 100kmi. Same results as ^. Oil held viscosity and not much wear at all. Oil was still nice gold colored, not much metal on the magnet and r&p gears looked great.
Again I'm sure my truck would still be on the road if I used another brand as well.
