I am about to swap in an 8.8 Trac-loc differential and am wondering what gear oil to use. I am thinking of switching to synthetic since you don't need to change it that often. So, first off, what brand of synthetic is best for gear oil? And second what weight should I use? 75w-90? 75w-140? 80w-90? 80w-140? Do the back and front diffs take the same weight? And with the L/S, if the oil says it has friction modifier in it already, should I still get a bottle and add it in? Also, how much oil do I need to get? In addition, im changing the fluid in the transfer case. Which is ATF is best? Should I use synthetic?
Thanks-
Thanks-