I took the truck in for a rear diff service yesturday. I came armed, with 5 qts of AMSOIL 75-90 Synthetic series 2000. I was expecting the worst when I asked my dealer to use that instead of the MOPAR stuff. He never even asked a question and said "Sure". I told him it was the weight and rating required by Dodge for my axle and to maintain my warranty. No problems... . is every dealer this nice????? Oo. Oo. 
