Maytag Legacy Washer SAV515DEWW - will not agitate

[tsmart]

I would like to request some help trouble shooting my Maytag washing machine.  The machine will operate as normal without anything in the machine, but  will stop agitating after putting in a few towels.  It will drain, spin, but not agitate.  Thanks for any help anyone can provide.

[Bailey]

This has a two piece agitator with the bottom part going back and forth and the top part going in a spiral to pull the clothes under. Empty it will look like the top part is working. With a load it won't work. Is the bottom part going back and forth with a load in it? If not you may have a transmission problem.