KM / WP DD - missing parts at top of agitator shaft ?

[jben]

When I took my transmission out I noted that my project washer is missing the two parts pictured that should be found on top of the spanner nut.

My searching found an old post by DADoES that helped me to identify them as (part's #7 = 3354845 and #8 = 8543666). However I'm still not understanding what the parts are doing; and since the agitator seemed to be working normal, I'm not sure how important it is that I find replacements.

I don't know when or why the parts went missing but since I'm putting time and $$ refreshing this DD washer I'd like to learn more about what you recommend ?

 

[DADoES]

 
Those parts insure that the agitator rotates at full speed with the basket during spin so the agitator-mounted, centrifugal fabric softener (if the machine has one) works properly, spins fast enough to dispense the softener.  The agitator shaft is disengaged during spin so receives rotational force only via whatever amount of friction it gets with the bearings and top seal.

One of the tabs on the plastic piece fits down into the basket drive block so it's positively-driven during spin.  The metal clip clamps to the agitator shaft, and the hooks on it mesh to the other tab on top of the plastic piece to help rotate the agitator up to speed.

Not necessary if there's no softener dispenser on the agitator ... helpful if there is one.