hey guys, what fluid does the diff take? i live in AZ, and it's a high of about 105 where I live, and it goes into the teens and 20's at night, so i need a good standard fluid i imagine. also, is it as simple is removing that plug on top and filling it up? any info would be great, my pinion seal is leaking evidently. Also, is the pinion seal easy to replace on my own? If so, i'll just do that real fast. Any help would be greatly appreciated!