This is an unusual problem. It might help to know your exact machine.
In top loading washing machines, the agitator is responsible for moving the clothes through the water and detergent and is driven by the output shaft of the transmission. The output shaft is normally splined and the center of the plastic agitator will have a matching spline to ensure a tight fit. Depending on the brand of washing machine, the agitator may be a single piece unit or a two piece dual action agitator. If the single piece agitator or the lower portion of a dual agitator does not oscillate back and forth during the wash cycle, or if the agitator can be turned on the transmission shaft, then the spline may be damaged and the agitator may need to be replaced. Most agitators are held in place with a bolt that threads into the top of the transmission shaft and is located below the softener dispenser or top cover. Some models use a small set screw in the barrel of the agitator just above the base to secure the agitator to the shaft, while some will use a rubber o-ring to provide a tight fit. When the retaining device is removed you should be able to lift the agitator from the shaft.
On top loading washers that use a dual action agitator, it is possible for the upper portion of the agitator to become disengaged from the bottom portion. The upper part is driven by directional cogs or “dogs” that are made of hard plastic and can wear out from hard use. If the upper portion of your agitator will turn in either direction or makes a grating sound during the wash cycle, then the directional cogs may need to be replaced. Remove the softener dispenser cover to access the retaining bolt securing the top portion of the agitator. With this removed you will be able to replace the directional cogs and the plastic bearing support
Sear sells the Estate Brand and also parts.
Problem is I don't know what's wrong with it.
Maybe @oldturkey03 or @ladytech may have some pregnant ideas.