Tools you'll likely need:
* Wrench: A wrench that fits the wiper arm nut. This is often a 10mm or 13mm, but double-check.
* Penetrating oil (like PB Blaster): This can help loosen a stubborn nut.
* Flathead screwdriver or similar tool (optional): May be needed to help pry the wiper arm if it's stuck.
* Shop towels or rags: To clean up any spilled fluids.
* Container: To catch any accumulated water in the wiper mechanism.
Procedure:
1. Disconnect the battery: This is a crucial safety step to prevent accidental electrical shorts. Disconnect the negative (-) terminal first.
2. Lift the wiper arm: Lift the wiper arm away from the windshield. This might take a little force, but be gentle.
3. Locate the nut: You should see a nut securing the wiper arm to the wiper motor shaft.
4. Apply penetrating oil (if needed): If the nut appears rusted or stuck, apply penetrating oil and let it soak for a few minutes to help loosen it.
5. Remove the nut: Carefully use your wrench to unscrew the nut. Turn it counter-clockwise. Have a container ready to catch any water that might spill from inside the mechanism.
6. Remove the wiper arm: Once the nut is removed, the wiper arm should come off. Sometimes it can be stubborn. If it's stuck, gently pry it off with a flathead screwdriver, placing the screwdriver between the arm and the shaft, being *extremely* careful not to scratch the windshield or damage the shaft. Wiggle the arm gently while pulling it straight off.
Important Considerations:
* Windshield Wiper Position: Before starting, it's often recommended to turn the ignition on, then turn the wipers on briefly so they move to their “park” position. This ensures there's less stress on the mechanism.
* Rust and Corrosion: On older vehicles, rust and corrosion are common culprits. Penetrating oil is your friend here. If you struggle, don't force it.
* Wiper Arm Return Spring: Be aware that there may be a spring inside the wiper arm assembly. Take care not to lose this spring.
* Alignment: When reinstalling the wiper arm, it's critical to get it properly aligned. There is usually a mark or groove on both the arm and the spindle to help ensure accurate placement.
Reinstallation:
Reverse the steps above to reinstall the wiper arm. Make sure the arm is correctly aligned before tightening the nut. Reconnect the battery once you are finished.
If you are uncomfortable performing this task yourself, it's always best to take your vehicle to a qualified mechanic. Damaging the wiper motor or scratching the windshield can be costly repairs.
