Also, don't forget that fluid flows easier when it's hot, so go run your VX around for awhile before you do the draining so it all flows out easier and more completly. You can also fish a syringe with a plastic ube on the end in the drain hole to suck out any remaining fluid. It is fairly worthless to do a fluid change if all the pieces of heavy metal stay in the bottom of the case after it is drained, just to get churned right back up into the system when it gets filled again. Also I know for sure that the Mobil-1 comes in pretty much two types of differential oil. The 75W90 is only good across a narrower temperature range. The 75W140 is good across a really broad range and costs a helluva lot more money. I used the 140 simply because temps in Nevada are absolutley insane. You go from sweltering Vegas summers to High Sierra winters, so it was almost a necessity. For milder climates, the 90 should be fine. I threw in the LSD additive when I did mine, don't know if it was necessary, but better safe than sorry.