I have put several of these in and had the same porblem with only one of them... What happened was that I forgot to install the stock piece off of the origional drive shaft.. Once I uninstalled it, and put the piece in, it worked fine. I can not remember if it was a spring or what. Read the directions and where it says to put the origional piece in, make sure itis there.. Hope that helps. That was the only problem I have had.