Whirlpool washing machine model number

Had a similar problem. What you need are new "dogs" inside the agitator cone. "Agitator Repair Kit"
Parts found here: http://www.partselect.com/PartDetail.aspx?Inventory=334622&SourceCode=6
Guarantee this will fix the agitator not spinning/working, unless the entire spindle isn't going back and forth.
I ordered this kit from these good folk and it arrived in 3 days.
All you need to replace these parts is a 7/16" socket with a 6" or longer extension & socket driver.
10 minutes, you can do this!
Hvae fun!