top agitator does not turn when mach is running

first removed the top dispenser[softener]by twisting it up.then pry out the round plastic cover that comes with the oring.after removing the cover
you'll see the 3/8 bolt that holds the agitator cam.removing the 3/8 bolt ,you can easily removed the whole agitator assembly and replaced it with the whole kit.on my washing machine the problem is the agitator cam 4 cogs[refer as dog ears,it is worn out completely.replaced it with the whole kit eventhough the problem is only the 4 cogs.the price of the kit is very cheap,and parts is delivered in short time.reminder,put locktite to the bolts thread before installing it back.easy less than 15 minutes installation.