98 Mustang 3.8 odometer problem

I have a 98 Ford Mustang auto with the 3.8L and my oddometer stopped working a while back after i had the gas tank replaced. I am getting ready to sell the car to get somethinh more suitable for 2 car seats and i want to fix this problem (if possible).

In 98 it was still a mechanical odometer. The most common is inside the odometer. The little plastic gears get some wear and splinter off parts that jam it up. Taking apart, cleaning and a small amount of 3 in 1 oil to lube has usually taken care of the problem for me. More rare but also a problem is the cable can break. To check this you disconnect both ends and check how it turns. Then the last possibility is the gear on the end of the cable that goes into the transmission is no longer attached to the cable and is spinning around on it or the teeth on it have worn away and it doesn't engage into the transmission.