I think the 05's have the 7/70 warranty. My front pinion seal was also leaking, was covered on my 3/36 warranty. I think there is a TSB about the American Axle diffs, fill hole is too high. My dealer says "fingernail below the hole". The gear oil is synthetic and theoretically should be very stable, not oxidize, and keep its original color (almost clear). Mine was burnt brown in color. I'm guessing my oil level was indeed high and the oil was foamed up by the gears.