Turns out I needed an Agitator Cam Kit. I found one on Ebay for $3 and $5 s/h. A video I watched on Youtube shows that this is about a 10 minute repair.
Basically the Agitator Clutch Dogs were worn down and no longer catching. So the lower "agitator" worked just fine, but the upper "auger" didn't spin very well and could be stopped with one hand.
Follow-up
The repair was far from 10 minutes... more like 2 or 3. This was a super simple repair, and I didn't need to replace everything... just the clutch dogs.
I found this doing a web search and think it will be helpful:
“5-5 AGITATOR
Most GE-designed washing machine agitators are not fastened to the shaft by any screws or bolts. To remove, simply tug upwards on the bottom of the agitator. There are exceptions; see "handwash" agitators below.
If you find that you cannot remove the agitator by pulling on it, try tapping the top of the agitator gently with a rubber or wooden mallet. If you still cannot remove the agitator, pry off the plastic cap in the center. Then cut out the little piece of plastic in the center of the hub with a knife; this will expose the top of the agitator shaft. (Figure GE-6)Hit it with a little WD-40 to loosen it.
GE-designed agitators have a removable rubber spline insert that connects the agitator to the transmission shaft splines (Figure GE-6.) If the splines are stripped, you can replace the whole agitator, or just the rubber spline insert.
Figure GE-6: Agitator Hub
To remove the insert, remove the plastic cap and cut out the center plastic piece as described above. Push out the old spline insert (it can be difficult.) To replace, put the new insert onto the top of the transmission shaft and push the agitator down onto it.
Hotpoint and JC Penney have a "handwash" agitator on some designs. The "handwash" agitator is actually a small agitator that fits inside the larger, main agitator.
The "handwash" agitator has a small screw underneath the metal disc on top of the agitator; make sure you remove it before trying to pull up on the "handwash" agitator. There are locking tabs that you must twist to remove the larger agitator from the smaller one.
Once the screw is removed, the "handwash" agitator should lift out easily. If not, tap with a rubber mallet a described above, or shoot some WD-40 into the screw hole.”
Source: http://www.appliancerepair.net/washing-machine-repair-5.html
Best Answer
after reading a ton of threads on agitators, watching videos, and speaking with livesupport and appliance repair people, i verified that the 7/16" agitator hold down bolt holds the upper agitator onto the lower agitator.
i removed the bolt from the lower agitator and didn't find any washers. i found something resembling a metal washer so i put a rubber washer then the metal washer over it. i put the cam kit on top then put the bolt back in and it held the upper agitator on the lower agitator. the washing machine works again!