I recently drove through a pretty good downpour here in southern AZ, and it brought into mind about something that I need to get taken care of. My wiper arms don't make good contact with the windshield, especially at higher speeds. The passenger side wipes more of the windshield than the driver's side, so for now I could switch them over. I imagine the spring tension on the arms is probably weak after almost 52 years. Is it possible to replace the springs, or is a whole wiper arm replacement necessary?