Many Whirlpool built 'direct drive' washers (including Kenmore, KitchenAid, Roper, and Inglis) use a 2 piece agitator. There are cogs called 'dogs' or 'dog ears' and a cam between the two halves of the agitator which can wear leading to a clicking/ticking sound and reduced movement of the top agitator section during the wash cycle leading to poor cleaning results. In most cases these worn parts can be replaced without much cost or difficulty.
The top section of the two piece agitator is usually removed by first pulling off the agitator cap then removing the inner cap. Underneath those there is usually a 7/16" bolt which will need to be unscrewed. Once removed, the top agitator half can usually be pulled straight up to access the defective components.
The clutch cam (shown at the right) and clutch dogs usually responsible for problems should be found in the now removed upper portion of the agitator assembly.