have a problem with wiper linkage bushings

While the linkage is apart, you could remove the drivers side wiper blade arm and try to rotate that pivot with your fingers. If it doesn't turn easily and/or has a lot of out of round movement, its worn out. The cast pivot housing is about 3 inches long but has only a 3/4 inch bronze bushing in each end. The forces wear the bushings sideways. To lower the pivot and rotate is 180 degrees will but the worn part of the shaft on a unworn side of the bushings which takes out a lot of the play and binding. This is only a temporary fix though. To renew a left pivot assembly requires a good shaft from a right pivot assembly donor and new bushings.