When the Moon is about two to three times its current distance from the Earth, then the Earth will lose its tug of war over the Moon to the Sun. At a distance of about 850 to 900 thousand kilometers from the Earth, the force of gravity from the Sun and Earth are about the same. I am not sure if you can even see the detail so it needs to be enlarged:
So on this enlarged scale the Sun is further away to the left by about six screen or book widths. The departure point is a ratio of roughly 173 times closer to the Earth than it is to the Sun because the Sun is about 30 000 times more massive than the Earth. 173 x 173 = about 30 000. The force of gravity decreases by the inverse of the square.
quoted from here:
http://www.flight-light-and-spin.com/why-moon-receding-from-earth.htm
;-j