Product review (4 stars): So far So good!!
Had it for about a month an so far it is working welll.  Just know that when folks talk about turning left to undo the old part.  They are saying that  the vice grip should be put on the broken wheel.  Clamp the vice grip on the brass part that is probably left from the broken base gear.  Use the screw driver on the bottom of your Magic Bullet to turn left with the screw driver (I was trying to turn left with the vice grips) and unscrew the bad part.  The new part should go on perfectly and like I said, it has been working well for about a month now.