Maytag MAV7000 AWW washing machine agitator won't spin freely.

I have a Maytag MAV7000AWW purchased in 2000. My understanding of one of the features of this machine is that the agitator reciprocates as driven by the motor (as in any normal design) but also sits on a ratchet-type gear mechanism which somewhat randomly advances the agitator several degrees in a counterclockwise motion (perhaps a less conventional feature) with each reciprocation throughout the wash cycle. This second motion surely improves the efficiency of the machine as it assures that the spiral blade on the agitator mixes clothes from top-to-bottom, in addition to the left-to-right mixing motion that is accomplished through reciprocation.

Under normal operation, the ratchet mechanism spins so freely that if you hold the door open but depress the safety switch to begin the wash cycle, you can advance the agitator along the ratchet by simply gripping the fabric softener dispenser at the maximum counter-clockwise point of reciprocation. I.e. the friction between the fabric softener dispenser and the agitator is sufficient to advance the ratchet mechanism. I do this from time to time to verify the this feature is still working properly and, hence, mixing clothes from top to bottom.

My problem is that it seems that the ratchet mechanism has become stuck or clogged w/ gunk. Recently, when I grip the fabric softener dispenser as indicated above, the fabric softener dispenser spins against the agitator, rather than the agitator advancing along the ratchet. I.e. the friction between the fabric softener dispenser and the agitator is no longer sufficient to advance the agitator alone the ratchet mechanism.

Can anyone recommend what I should do to restore the ratchet mechanism to its proper operation? If my suspicion is correct, can you tell me how to remove the agitator to clean/repair/replace part/all of the ratchet mechanism? And what parts and I likely to need to purchase? Or, of course, tell me if I'm completely off base. Thanks for your advice.