? about the rear end

Have the car as level as possible and keep on filling until the fluid starts coming back out of the fill hole.

VERY IMPORTANT! If you have a TractionLok limited slip rear end make sure you add a bottle of FRICTION MODIFIER which you can buy at your Ford dealer. If you fail to do so you can mess up your clutches back there and you might notice the axle trying to lock as you go around corners.