2021 Peterbilt 579 Wiper Blade Sizes & Replacement Guide

Maintaining clear visibility is critical for safety, especially when you are behind the wheel of a heavy-duty commercial truck like the 2021 Peterbilt 579. Whether you are navigating long hauls through torrential rain, sleet, or snow, a dependable set of wiper blades is a must-have for your rig.

Below is your complete guide to the wiper blade sizes, attachment types, and top aftermarket replacements for the 2021 Peterbilt 579.

Quick reference

Note: Always verify your current blade lengths before purchasing, as some fleet specifications may alter the windshield setup or utilize slightly different arms (e.g., 22"). The Peterbilt 579 does not come equipped with a rear wiper.

Best aftermarket replacements

When swapping out the factory blades on your 579, you want something built to withstand highway speeds and massive amounts of road spray. Here are the top aftermarket cross-references, ranked by general price tier:

• Trico Force (Premium): Trico offers excellent heavy-duty and high-wind options. The Force line features a swept-wing spoiler that prevents wind lift, keeping the blade pressed firmly against the Peterbilt's large windshield.
• Bosch ICON (Premium): Known for extreme longevity and clear, streak-free performance. The ICON’s dual precision-tensioned steel springs distribute uniform pressure along the entire length of the blade.
• PIAA Si-Tech (Premium): Silicone blades that actively coat your windshield with a water-repellent layer. Highly durable against UV rays and extreme temperatures.
• Rain-X Latitude (Mid-Range): A popular choice that contours well to curved windshields and often includes a water-repellent coating.
• Michelin Stealth (Mid-Range/Budget): Features a hybrid design with a smart-hinge cover to protect the blade from snow and ice buildup—perfect for winter driving.

Attachment style

Commercial trucks often utilize more robust wiper arms than standard passenger vehicles. The 2021 Peterbilt 579 typically features a heavy-duty wide hook or a saddle attachment. Unlike the standard 9mm J-hooks found on most cars, heavy-duty hooks are wider (often 12x4mm) to handle the torque and weight of large commercial blades. When buying aftermarket blades, ensure the package includes the heavy-duty adapter.

How to install

Replacing the wiper blades on your Peterbilt 579 is a straightforward process, though you may need a step stool to reach the windshield comfortably.

1. Lift the wiper arm: Carefully pull the wiper arm away from the windshield until it locks in its upright position.
2. Remove the old blade: For hook attachments, press the small release tab on the underside of the wiper arm where it meets the blade. Slide the blade down toward the base of the arm to unhook it.
3. Prepare the new blade: If using an aftermarket blade (like the Bosch ICON or Trico Force), snap the appropriate heavy-duty wide-hook adapter onto the center of the new blade.
4. Install the new blade: Slide the new blade onto the wiper arm hook. Pull it upward until you hear a distinct click, indicating it has locked firmly into place.
5. Lower the arm: Gently lower the wiper arm back against the glass. Never let it snap back, as the bare metal arm can crack the windshield.
6. Test: Turn on the ignition and test the wipers with washer fluid to ensure they are secure and functioning correctly.

When to replace

Wiper blades are wear items that degrade from UV exposure, extreme temperatures, and general use. For commercial drivers putting high miles on a 2021 Peterbilt 579, we recommend replacing your wiper blades every 6 to 12 months.

You should replace them sooner if you notice any of the following symptoms:

• Streaking or smearing across your line of sight.
• Chattering or skipping over the glass, which indicates the rubber has hardened.
• Squeaking noises during operation.
• Visible damage, such as torn rubber or bent frames.

Need wipers swapped fast? Find a shop on Repairius.