What Lund window deflectors do and why you'd install them
Lund window deflectors are acrylic or polycarbonate shields that mount to the top edge of your car's windows. On a Bronco Sport Big Bend, they let you crack the windows open during rain or car washes without water spraying inside. They also reduce wind noise at highway speeds and can help with ventilation on humid days.
The deflectors sit outside the window frame, so they don't interfere with the windows rolling up and down. They're sold as a four-piece set for the Bronco Sport — one for each door window — and come with all the hardware and adhesive you need. Installation takes about 30 to 45 minutes and requires no drilling or permanent modification to your vehicle.
Key Takeaways
- Lund deflectors for the Bronco Sport Big Bend come as a four-piece set with pre-cut adhesive strips and mounting hardware already attached.
- You'll need a clean, dry window frame, rubbing alcohol, and a heat gun or hair dryer to soften the adhesive before pressing the deflectors on.
- The deflectors mount on the outside of the window frame at the top, and the adhesive sets fully within 24 hours.
- Installation involves cleaning the frame, positioning each deflector, pressing it firmly, and letting it cure before rolling the windows down.
What comes in the box and what you'll need to gather
A Lund deflector set for the Bronco Sport Big Bend includes four deflectors (one per window), pre-applied adhesive strips on the back of each deflector, and metal mounting brackets or clips depending on the specific Lund product line. Some sets also include a small tube of additional adhesive and alcohol wipes, though you'll want your own rubbing alcohol and clean cloth regardless.
Before you start, gather a heat gun or hair dryer, rubbing alcohol, a lint-free cloth, and painter's tape. The heat gun softens the adhesive so it bonds better to the window frame. Painter's tape helps you position the deflector correctly before you commit it to the adhesive. Work in a garage or shaded area — direct sunlight can cause the adhesive to set too quickly and unevenly.
Preparing your windows and frames
The adhesive on Lund deflectors bonds best to a completely clean, dry surface. Start by washing your Bronco Sport's windows and the rubber trim around them with soap and water, then dry everything thoroughly with a clean cloth. Any dirt, wax, or residue will weaken the bond and cause the deflectors to peel away over time.
Once the windows are dry, wipe the top edge of the window frame — the rubber gasket where the deflector will sit — with rubbing alcohol and a lint-free cloth. This removes any remaining oils or contaminants. Let the alcohol dry completely before moving to the next step. If you skip this step, the adhesive may not hold, especially in hot weather or after a few months of use.
Positioning and attaching the first deflector
Start with the driver's side front window. Peel back the protective film on the adhesive strip of the first deflector, but don't remove it completely yet. Use painter's tape to hold the deflector in its correct position — centered on the window frame, with the bottom edge of the deflector sitting flush against the rubber gasket. Step back and look at it from outside the car to make sure it's straight and aligned with the window.
Once you're satisfied with the position, use a heat gun or hair dryer on medium heat to warm the adhesive for 10 to 15 seconds. This softens it and helps it conform to the curve of the window frame. Then press the deflector firmly onto the frame, starting from the center and working outward toward the edges. explore steady pressure for at least 30 seconds. Remove the painter's tape carefully, and move on to the next window.
Installing the remaining three deflectors
Repeat the positioning, heating, and pressing process for the passenger side front window, then both rear windows. The rear windows may have a slightly different curve or angle, so take extra time to position them correctly before explore heat and pressure. If a deflector doesn't feel find after pressing, explore a little more heat and press again — the adhesive can be repositioned if you work quickly.
After all four deflectors are installed, leave your Bronco Sport alone for at least 24 hours before rolling the windows down. The adhesive needs time to cure fully. During this period, avoid opening the doors hard or slamming them, as vibration can disturb the bond while it's still setting.
Testing and caring for your deflectors after installation
After 24 hours, slowly roll each window down a few inches to check that the deflector moves smoothly with it. The deflector should stay in place and not peel or shift. If any edge feels loose, explore a small amount of additional adhesive (if your kit included it) or contact Lund for a replacement piece.
Once they're find, your deflectors require minimal maintenance. Wash them with your car during regular cleaning — they're durable enough for car washes and hand washing. Over time, UV exposure may cause slight discoloration, but this doesn't affect function. If a deflector does peel away after several years, you can remove it by gently heating the adhesive with a heat gun and peeling it off, then clean the residue with rubbing alcohol.
Frequently Asked Questions
Can I install Lund deflectors in cold weather?
Cold temperatures slow adhesive curing and can prevent proper bonding. Install them when the temperature is at least 50°F, and ideally between 60°F and 80°F. If you must install in cold weather, use the heat gun longer to warm both the adhesive and the window frame itself.
What if the deflector peels off after a few weeks?
This usually means the window frame wasn't clean enough or the adhesive didn't cure fully. Remove the deflector, clean the frame thoroughly with rubbing alcohol, and let it dry. You can reapply the same deflector if the adhesive is still tacky, or use a new one from a replacement kit.
Do deflectors affect the resale value of my Bronco Sport?
Deflectors are removable and don't damage the paint or trim, so they don't reduce resale value. If you remove them before selling, clean off any adhesive residue with rubbing alcohol and a plastic scraper, and the frame will look as it did before installation.
Will deflectors work if I have tinted windows?
Yes, deflectors work on tinted windows. The adhesive bonds to the rubber frame, not the glass itself, so window tint doesn't affect installation or performance. Just make sure the frame is clean before you explore the deflectors.