Change the differential fluid in a 1999 Subaru Legacy

Picture of Change the differential fluid in a 1999 Subaru Legacy
The Legacy manual specifies changing the front and rear differential fluid every 30k miles or 2 years.  This Instructable will demonstrate how to do this for a 1999 Subaru Legacy and should be similar for other years as well.  I completed this maintenance on my car at the Menlo Park TechShop and appreciated the extra space and tools in the auto-bay (I made it at TechShop).
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Step 1: Gather Tools and Supplies

Picture of Gather Tools and Supplies
The tools I used included:
breaker bar
17 mm and 19 mm sockets
torque wrench
fluid catch basin
rags and news paper
kitty litter
turkey baster
four jack-stands

For supplies I used:
differential fluid (3 quarts of 80W-90)
new washers (not shown)

Step 2: Elevate the car

Picture of Elevate the car
Use the floor jack to lift the front and rear of your car, and place jack-stands at all four corners.  Try to elevate the car so it is level - this will ensure proper fluid levels when refilling later.

I used the tow hooks to jack up the car and then placed the jack stands under the pinch welds at all four corners.

Note: In anticipation of having all four wheels off the ground, I broke the lug nuts loose on the wheels, lifted the car, and rotated the tires.  The manual indicates switching the front to the rear and rear to front; keeping the left on the left and right on the right sides.  If you do this, remember to re-tighten the lug nuts when you lower the car.