I HAVE A 97 FORD EXLORER SPORT ODOMETER STOPED WORKING HELP?

HI EVERYONE. I NEED SOME ADVICE ON HOW TO FIX MY ODOMETER WITH OUT CHANGEING IT TO A NEW ONE WITH DIFERENT MILE'S. EVERY THING WORKS FINE ON THE DASH BUT THE MILE'S HIT 70.788 MILE'S & JUST STOPED WORKING. ANY ADVICE ON WHERE TO LOOK AT?. IM TRYING TO AVOID SWITCHING IT TO ANOTHER WITH DIFERENT MILES. THANK YOU.