BMW E70 Replacing a Windshield Wiper Mechanism
Let’s consider the following situation: you turn on your windshield wipers, and while the blades start moving, they stop suddenly, accompanied by a grinding noise. This likely means the gear inside the wiper motor has failed. Here’s how to replace the mechanism step by step:
1. Remove the Wiper Arms
- First, remove the wiper arm caps.
- Use a 16mm wrench to loosen and remove the nuts securing the arms.
- Take off the rubber seals and plastic covers.
- If you have a puller tool, use it to remove the wiper arms. If not, carefully wiggle the arms loose. Be gentle to avoid damaging the wiper linkage assembly.
2. Access the Wiper Mechanism
- Remove the clips and the plastic panel covering the wiper mechanism.
- Unscrew the four bolts securing the mechanism using a T30 Torx bit.
- Disconnect the electrical connector to the motor.
3. Replace the Wiper Mechanism
- You can replace the entire wiper assembly, which costs about $500 (part number 7200510). This is the best option for durability but comes at a higher cost.
- Alternatively, you can replace just the motor. A Chinese aftermarket motor costs around $150 but may not last as long.
4. Install the New Mechanism
- Install the new wiper assembly and tighten the bolts to 10 Nm.
- Reattach the plastic panel and secure it with the clips.
- Reinstall the wiper arms.
5. Align the Wipers
- Turn on the ignition and cycle the wipers to ensure they stop in the correct resting position.
- For BMW E70 models (specifications vary for other cars):
- Driver’s side blade: Distance from the edge of the windshield should be 90 ± 3 mm.
- Passenger’s side blade: Distance should be 103 ± 3 mm.
Proper alignment ensures full windshield coverage and prevents interference during operation.
6. Verify Alignment
- When correctly positioned, the blade tips should face each other.
- Tighten the wiper arm nuts to 35 Nm.
7. Check the Wiper Blade Angle
- Use a specialized wiper blade protractor to check the angle.
- Remove the wiper blade and attach the protractor to the wiper arm.
- Passenger’s side angle: -4 degrees.
- Driver’s side angle: -5 degrees.
- If the angle is incorrect, adjust the wiper arm using a dedicated tool.
8. Reassemble and Test
- Reinstall all plastic panels, ensuring they fit securely in the slots to allow proper water drainage.
- Test the wipers to confirm proper operation and alignment.
By following these steps, you’ll ensure your windshield wipers work effectively, keeping your visibility clear and driving safe.
