Amsoil makes a severe gear diff oil that is AWESOME; you'll never need to change it again unless you get water in it~

 

Multiple problems all at once... None of that mess may be from the diff or axle... when I get this all figured out I'll update.

 

If the oil is thin, brake fluid. Thick=gear oil. IMO gear oil has a foul smell but you get to like it after a while! A small finger wipe and taste test will tell you if it's brake fluid. -a very small amount on the tip of your toungue will taste very bitter.

 

I'll explain more later... Out the door for work. But I'm 99% sure its Valvoline 20w 50.