I contacted the artist, and he kindly provided the Blend file. Unfortunately, he's not responded back to the questions I asked him. this file was made two years ago and works perfectly.

Can someone PLEASE take a look at it and tell me how he got the track to STAY on the Path and how he got the wheels to rotate automatically as well?

http://infin3d.servebeer.com/taxonomy/term/104

Here's his YouTube video:
http://www.youtube.com/watch?v=vDhHyaK76OY&feature=channel_page

Here's my Original file (Before coming across the above artist's video)
http://www.filefactory.com/file/ag8gfc2/n/TankTrack_SHARE_rar

You can see that the track keeps coming off of the path here:
http://www.youtube.com/watch?v=TpDNQtf84hk

PLEASE don't bother providing a tut to the soft Caterpillar approach. It's WAY TOO complicated and I get lost in it far too easily. The above method is clearly MUCH simpler and works just as well.

Thanks

I've got the tracks figured out for you.  I think I explained it as simply as possible.

Tank Tracks

I just put this together for you.

I just looked at your file.. Looks good.. I see one issue..  looks like you used a path instead of a Curve Circle like the other guy did..

If you rotate the path on the Z axis to turn your 'track' it explodes..
I don't seem to have this problem when using a Curve Circle...

Thanks RedDog9. But here's the problem.

I've always used a Bezier Circle.
The thing is that I originally used a Curve Modifier to place the track to the path (Bezier Circle). Which (in the end) is the same thing as Parenting with a "Curve Deform." But for argument sake, I followed your tut to the letter. Or at least as far as I could. ;)

I need the track to stay on the path (Bezier Circle) no matter where I place or rotate the path. RedDog, When I tried it, I had to move the track on it's Z axes in order to get it to move along the path.  And if I move the Bezier Circle on the X axis at all, the track freaks out for some reason. I've tried copying the Empty's location, but then the track wouldn't move at all.
And if I try rotateing the Bezier Circle in edit mode (to move the track on the X axis) the Bezier Circle ends up twisting. :(

I'll try recording the process I went through originally so it's easier to understand.

Okay, my computer sucks too much to try and record my process and my attempt at your tutorial. So I'll just type it simply to save time.

1-Crate track (lined on X axis).
2-Create Bezier Circle and rotate it 90degrees on the X axis (while in Edit mode)
3-Remove the Twisting sections and add new points to fix the glitch
4-Select the track and add a Curve Modifier and imput the Bezier Circle's name.
5-Rotate the track (if needed) to the correct alignment.

I've also tried:
1-Crate track (lined on X axis).
2-Create Bezier Circle and rotate it 90degrees on the X axis (while in Object mode)
3-No twist appear
4-Select the track and add a Curve Modifier and imput the Bezier Circle's name.
5-Rotate the track (if needed) to the correct alignment.

But problems always happen the track.

Someone needs to make a video Tutorial so we (at least me) can see exactly how it's done first hand.

Here's my blend file

Track.blend

Maybe I'm mistaken, but the file you posted used a "Path" instead of a "Bezier Circle".   You're correct, when I tried moving your rig around, the tracks would fly off the path when moved in one direction. 

I've used a Bezier Circle in my example above.   Rotating / Moving the curve in any direction and the tracks stay on the curve.  Moving the 'track' along the global Z axis is what will make them rotate around the Bezier Circle.  This is what the guy did in the other file. .  He used a Lattice as a handle in order to move the track up and down, there by rotating them around the Curve Circle.

Reddog9,

It is a Bezier Circle. I just renamed it 'path' to simplify things at the time. Sorry for that little confusion.

 I've studied the other artist's file a lot. The lattice objects that the tracks are parented to only have keyframes on the "Y axis" so he's not moving it on the Z axis as we thought. This is the main thing that's throwing me off. That and the fact that the wheels (and their lattices) are rotating on the same axis perfectly without any axis being locked.