After draining it I always fill the rear case until it pours out the fill hole, then pull the shifter and add more to the front. I used to just fill the rear case, drive around the driveway in 4wd, and recheck it, but that took too much time. Just filling from the rear never seems to get enough into the front case in my experience. I don't even run the plastic trim around the tranny/front case shifter so it takes about a minute to remove my shifter.
