Do your windshield wipers leave unwiped spots for no apparent reason, even after you replaced the blades?
All wiper arms have a hinge at the base that allows the arm to flex as it follows the curvature of the window. If the wiper skips over certain spots, even with a new blade, chances are the hinge is binding from corrosion. It’s most common on rear window wipers since they’re used less often.
You can oil the hinge, but that’s just a temporary fix—the corrosion and binding usually return. To fix the problem permanently, replace the wiper arm (available at an auto parts store).
1. All wiper arms fit onto a splined shaft.
2. Some wipers are held with a retaining nut. To replace, lift the plastic protective cover and remove the retaining nut. Then pull the arm off the splined shaft.
3. Other wipers have a locking clip. Lift the wiper arm a few inches off the glass and slide the locking clip out. Then lower the arm and pull it off the splined shaft.