To change a vehicle’s rear differential fluid, jack the vehicle up, remove the differential’s drain plug, pump out the spent differential fluid, use a funnel to add new differential fluid, replace the drain plug, and lower the vehicle back down. You need a jack and jack stands, a wrench or 1/2-inch-drive socket wrench, a hand pump, a funnel, and a container to catch the old fluid. Refer to the vehicle owner’s manual to determine the appropriate replacement fluid.
To begin replacing the rear differential fluid, park the vehicle on a level surface, jack it up, and lower it onto jack stands. Find the drain plug for the differential; the location is usually on the differential’s back, facing the back of the car. Use a wrench to remove a bolt that serves as the drain plug, or insert the tip of a 1/2-inch-drive socket wrench into drain plugs with recessed center squares, rotating the plug counterclockwise.
Insert the inlet hose of a hand pump into the opening of the drain plug, and pump out the old differential fluid. Place the pump’s outlet hose into a container to catch the used fluid. Continue pumping until you remove all the differential fluid. Insert a funnel into the opening, and pour the new fluid into the differential, filling it until it reaches the drain plug opening.
Remove the funnel, and replace the drain plug. Remove the jack stands, and lower the vehicle down.