How often do you change your Front/Rear Differential Fluid?

wnjj wrote:
Fluid may be "cheap insurance" but you're slightly increasing the risk of failure. What if you make a mistake when changing it? E.g. Wrong level of fluid, contamination or create a leak. Some things are better left alone for longer periods.

While I don't think changing diff juice as a matter of course every 3-4 oil changes is even remotely necessary, the slight risk of failure is really non existent. Like saying brushing your teeth twice a day doubles your risk of getting toothpaste in your eye!