If your wiper makes a loud noise when scraping the glass, the common reasons are as follows. I will tell you the solution, you can save it:

- The wiper support steel frame is not installed correctly: this will cause the wiper to rub against the glass surface when working.
Solution: Check the steel frame installation to ensure it is correct. - Foreign objects are mixed between the wiper blade and the windshield: sand, pebbles and other foreign objects are sandwiched in the middle, and there will be abnormal sounds when running.
Solution: Clean the foreign objects to solve it. - The spring of the wiper arm is too tight: the spring is adjusted too tight, and the pressure is too high when wiping the water, causing noise.
Solution: Loosen the spring appropriately. - The friction surface of the wiper blade is excessively worn: long-term use will cause wear and tear, and contact with the glass will cause noise.
Solution: Replace the new wiper blade. - The friction surface of the wiper blade is not smooth or deformed: uneven or deformed causes irregular contact and noise.
Solution: Replace the wiper blade. - The wiper itself is aging: each component loses its original performance due to aging.
Solution: The entire wiper needs to be replaced. - The wiper rubber strip is aging: rubber products are prone to aging and hardening after long-term exposure to wind, rain and sun, which is more obvious in winter.
Solution: Replace the wiper blade with a new one, usually once every one to two years. - There are impurities on the glass: impurities on the surface of the glass will produce noise when wiping.
Solution: Clean the glass. - The wiper linkage mechanism is damaged: the motor, transmission rod or connecting rod and other components are damaged, resulting in abnormal noise when wiping the glass.
Solution: Repair or replace the damaged parts. - The wiper frame is twisted upward: If there is an abnormal noise only when going up, it may be that the frame is twisted upward.
Solution: Stop the wiper in the middle position, wrap the steel frame with cloth or soft material, hold the wrapped part with a wrench or pliers and twist it downward until the abnormal sound disappears.

Conclusion
Although the wiper looks simple, it has a great impact on our driving safety. So friends should also pay attention to regular maintenance!
