Rotating Component does 180 degrees back and forth. How do I do full rotations?

I'm trying to animate the wheels on this crane (not as important as the later wheels I'm drawing up right now) and I can't get a full rotation. I tried everything to my understanding to use motion transition constraints against the rail or manually rotate them in the Studio. The former never worked for me and later keeps rotation 180 clockwise, then 180 ccw, and back and forth. Can anybody explain what I need to fix? I started a fresh document with no joints for I figure I must have been screwing up on that. If anyone can, please take a look at the files and see if he or she can solve this drafting quarrel.

https://docs.google.com/open?id=0B1StefGFfwrxNER3OU5vbDlUWXlsZmI0bnpCdzR1Zw

Thanks for the help!

How are you doing the rotation? (I don't open files that aren't attached here) Drive Constraint?

Did you use a Directed Angle constraint?

I tried the directed angle constraint and that's when I get 180 cw and ccw but no full revolution. I'll try the drive constraint right now; I got errors nonstop on that before, but I think because of the file at the time.

Corrected, I had Undirected Angle Constraints. Now they are Directed Angle Constraints and work perfectly in the full 360 and beyond. Thanks for that tip!

While I have you, I'm trying to guide a truck through an industrial lot (low detail) and wonder if there is a way to make the truck follow a path?

Have you gone through the Wasim Younis book?