Agitator problem top part of agitator doesn't work. Pried off the ''lid'' to it and see some crumbled up off yellow plastic stuff at the bottom. I am going to assume that this was something round with gears or something simular. My question is with no diagram of the inside of an agaitator how I do I look for a replacement of the broken part? Thank you Kindly, Deb

It sounds like the agitator dogs are worn (in your case they have likely broken into little pieces) and need to be replaced. Remove the agitator cap and the bolt that holds down the agitator. With the bolt out you can remove the top section of the agitator (auger) where you should see 4 small white or beige plastic gears (dogs). . Replace those and it should be ok.

The part number is 80040

This part is common among most Kenmore/ Whirlpool models. If it doesn't look like the right part, please post the model number and I will try to assist you further.
Good luck!