The link to the agitator that macboy91si has posted that is in Bowling Green, MO is not the right agitator. I had them send me close-up pics of the underneath side of the agitator and there is no place for the stop ring to pop into. If you look closely at the base of the column right before the skirt starts down you will see a set screw. They also sent me pictures of the set screw.
This is an agitator that came out of one of the very first orbital drive machines; before they redesigned the agitator. I know because I bought one from Sears around '92 or so. The orbital drive came in in the late 1980's, I think, so the washer they sold me must have be an older stock machine that had been setting around. When I first looked at the machine at the store it looked like the old long stroke machine.
They brought it in to the basement and started to hook it up. I said leave it alone. I'll hook it up. That's all I need from you. I balanced it, read all the instructions, hooked it up and we put 5 pairs of jeans in it. We had 29-32 inch waists, so the machine wasn't over loaded. It started that fast frantic sound. I opened the lid and depressed the button. I had been deceived. This was not the Maytag I knew. The jeans wouldn't even turn over. I immediately called Sears and told them to come and get the damn thing and that it wasn't worth crap. I said a Maytag isn't supposed to act that way and I won't have it. Get it out NOW! It was gone the next day. I was so disappointed.
I had just thrown out my solid tub Speed Queen from the mid to late '60's. I was so mad at myself. I wanted it back. I still do.
Anyway, that's the agitator you're looking at. It doesn't work with the stop ring, so don't get it.
Oh, I think that's what Tom just told you. Sorry.