What Are Wiper Arms?
While power and speed are regulated by the combination motor and gearbox, several different mechanical components are also crucial to convert the power into function. The wiper arms help to support the frames and blades and make sure that movement is carefully regulated.
How Do Wiper Arms Work?
When power is provided by the wiper motor and converted into a usable form by the worm gear, it must be connected to the wiper arm through a special linkage. This linkage is fixed to a stud, also known as a “pivot point,” onto which the wiper arms are carefully fitted. These arms are designed to only pivot through a specific range of motion, so the wiper blades themselves go through a predictable arc of movement on the windshield. They need to endure high levels of torque during the operation and must be mounted carefully so that they do not loosen.
How Are Wiper Arms Made?
Windshield wiper arms are typically made from galvanized steel, or in certain circumstances stainless, to help avoid damage from corrosion. They are precast according to specific dimensions based on manufacturer requirements for each vehicle model, and protective paint is applied to avoid rust and corrosion.
Why Do Wiper Arms Fail?
- They can be bent out of alignment.
- They can come loose.
- They can suffer from metal fatigue or corrosion.
What are Symptoms of Failure?
- The wiper blades can “streak” on the windshield due to incorrect positioning of the arm.
- Blades can “stutter” as they pass across the windshield.
- Blades can lose contact with the windshield altogether.
- Blades may fail to move at all.
What Are the Implications of Failure?
- The system will fail to clear precipitation from the windshield, making it difficult to drive in bad weather.
- The frame of the blade can come into contact with the windshield, causing damage.