If you're going to consider replacing the shaft don't forget the bearing, DieselPlace has some excellent post in the archives and some other fixes not readily available by a Google search....
http://www.amazon.com/Dorman-905-51..._UL160_SR135,160_&refRID=0VKBNJYF9D6PR0FTJ0DS
How much of a pain is it to replace the bushing ?