Noisy wipers

Can anyone help. I just replaced wiper arms and blades, but blades chatter across the windshield. Tried cleaning blades and windshield with ammonia........very slight improvement, but the problem is still there. Tried replacing the blades again, same problem. Could the wiper arms be applying too much pressure to the blades ? If so, any way to correct this ? Thanks in advance for any responses.

If your windshield has a lot of pits in it, there may be nothing short of a new windshield that will solve this. If it is ok, the angle of the wiper arm or both arms may have changed by being bent at some time. Watch the wipers as they go back and forth... do the blades sweep as the move, or do they go against the direction they are traveling?