pic: 222 3 speed closeup/cutaway

[team222badbrad]

These pictures give you more detail of the transmission

I will try to post more information later but I have to leave right now

(edit)
I am back. Earlier you asked what prevented the balls from falling through. As seen in the second picture their are 2 different size hole. Once that fits the bearing which are 5/16 in size. The red piece as shown in the above picture can slide back and forth on the orange shaft. The blue springs are used to prevent the ball bearings from being forced in the gear when the slots are not lined up. The red thing in the picture does not really have flat spots on them in the real robot, I just made it that way to make it easier to constrain the balls to them in Inventor.

The gear is also offset from the balls in the picture so you can see the insides better. The gear is really in the center of the ball bearings.