I think you have replaced them in slightly the wrong position. They are located on very fine splines so it is very easy to replace them in the wrong place, being one spline off on either or both arms will result in a big difference at the outer end of the arm.. When they operate are they very close together when they sweep and when they get to the edge of the screen do they touch the edge. I would remove them and reset them so that when they park they are at their lowest.