I thought I would share this with my Titan brethren. I had the oil and rear diff. fluid changed today. I'm from the old school and I get rid of factory oil at 1000 miles. The dealer did the oil change (first one is free). I went with Mobil 1. I did check the oil level prior to the change and it was where it should be, with the factory oil looking like honey. Mileage is 1133. The rear diff. was a different story. (MIleage at this point is 1177). I did this job myself. I got an old paint can and pulled both the fill and drain plugs. This oil was black, with a thick blob of "metal fuzz" on the drain plug. I cleaned the drain plug, applied a fresh bead of Permatex thread sealant, installed and torqued to 20 ft.-lbs. Then filled with about 2.25 quarts of Mobil 1 75w-140 gear lube. Cleaned the fill plug, applied Permatex thread sealant and torqued to 25 ft.-lbs. I was pleased to see the engine oil looking well, but the rear diff. oil was something to behold.