Pennsylvania my ex wont sign divorce papers when can i get divorced?

we were legally separated in pennsylvania 8/4/2010 and I legally served him 6/1/2011. He is saying he won't sign the paperwork. Isnt there a provision that after 2 years the divorce becomes final (note custody has been finalized, property has been finalized, and both parties waived alimony and waived child support). If the 2 year rule does apply, is it 2 years after the legal separation date or 2 years after the serving of the divorce complaint