How to constrain a cycloidal gear in CREO 2.0 Mechanism

Can someone tell me how to constrain the cycloidal gear above in CREO 2.0 Mechanism?  I've used the slot and pin constraints, and the gear stays within the bearings as it should when the input shaft is rotated.  But the gear rotates erratically, sometimes it moves much more than it should and sometimes doesn't.  The gear should "rotate" 51.43 degrees with each complete rotation of the input shaft.

Thank you.