Rust Resolution Proves Elusive for Our 2021 Ford F-150


Like many 2021 Ford F-150 owners, we discovered our brand-new pickup truck had significant amounts of rust on its underbody when the phenomenon was first reported by the Detroit Free Press (subscription required) in March. We bought the winner of our Best of 2021 award to report on what it’s like to own the 2021 F-150 hybrid. Needless to say, we’ve been busy.
Related: Owning the 2021 Ford F-150
- ${price_badge()}
- ${battery_badge()}${ev_report_link()}
- ${hot_car_badge()}
- ${award_badge()}
- ${cpo_badge()}
${price_badge_description}
The EV Battery Rating is based on this vehicle's current expected range relative to the vehicles expected range when new. ${battery_badge_text}
Certified cars are manufacturer warrantied and typically go through a rigorous multi-point inspection.
This car is likely to sell soon based on the price, features, and condition.
${award_blurb}
${award_two_blurb}
Shop the 2021 Ford F-150 near you


We’ve heard from other 2021 F-150 owners who, like us, were surprised and disappointed to discover rust on the underside of their truck. We were curious what our local Ford dealer would have to say about the rust, but we also wanted an independent mechanic’s assessment to know whether it was something that should concern owners. We spoke with both and also reached out to J.D. Power, which publishes the annual Initial Quality Study, for additional perspective.
While the independent mechanics we spoke with weren’t concerned that the rust under our F-150 would affect vehicle serviceability or create problems for owners, the characterization of it as normal at the dealership level that we and other owners experienced could have future repercussions for Ford.
The Mechanics’ View
We first took our F-150 to two local independent mechanics, both of which put our truck on a lift to get a better look at the underbody. Neither were alarmed by the amount of rust on our truck, and one noted that the rusty section at the end of the axle tubes wasn’t a structural concern since the metal was so thick.

The mechanics essentially echoed Ford’s initial response to our rust inquiries. In an emailed statement from March, a Ford spokeswoman said that “while some F-150 underbody steel components may show signs of surface rust, this will have no impact on part performance or life.”
The other mechanic also said underbody rust on new vehicles is fairly common in the Chicago area in which Cars.com is headquartered due to the region’s reliance on road salt during winter months. This may have been a contributing factor with our truck — we purchased it in January — but it doesn’t explain the rust on the truck of one reader who lives in a snow-free region of the U.S., or another who sent us photos of the rusty rear differential housing on his truck with just 37 miles on the odometer. The below gallery contains photos we received from readers that show various areas of rust on their 2021 F-150s.














To address the rust, both mechanics recommended that the undercarriage be undercoated. There are different types of undercoating, with fluid-film treatments that need to be reapplied to remain effective as well as abrasion-resistant coatings that are more permanent.
We called two undercoating companies in our area, and both quoted prices of around $500 for a complete underbody coating for our truck. For those so inclined, there are also do-it-yourself options that cost significantly less and may be suitable to spot-treat areas that have developed rust — especially if you live in a part of the country where the likelihood that the undercarriage will develop additional rust is remote.
The Dealership’s View
We’d received an alert in our FordPass app that our truck’s integrated trailer module needed to be reflashed, and when scheduling that service with a nearby Ford dealer, we also mentioned the rust on our truck’s rear axle and other underbody components. The service advisor said they’d look at it during our visit.
The service appointment was straightforward, taking only about an hour, and when the trailer module update was finished, our service advisor walked us over to our truck to look at the rust together. He said it was normal for our area. After taking a look at four new 2021 F-150s sitting on the dealer’s lot while waiting for our truck, I can see why the rust might seem normal: All four trucks had rusty rear differential housings.
More From Cars.com:
- Here’s How Much the 2021 Ford F-150 Costs
- Our 2021 F-150 Had Problems After 9 Days, 242 Miles
- We Bought a $189 Tonneau Cover for Our $78K Ford F-150
- Breaking Down the 2021 Ford F-150’s Towing Capacities
- How Do Car Seats Fit in a 2021 Ford F-150?
J.D. Power’s Perspective
No one we spoke with was concerned that the rust on our truck would create durability problems, but that’s not the only way new vehicles are judged. One of the key studies of new vehicles is J.D. Power’s Initial Quality Study, which measures the number of problems per 100 vehicles in the first 90 days of ownership.
The Initial Quality Study looks at 223 problems organized into nine categories, including an Exterior section that covers things like paint, fit and finish, and any blemishes when new. The survey also has a section for open-ended comments.
The redesigned 2021 F-150 wasn’t included in the most recent study, which covers vehicles from the 2020 model year. The 2020 Toyota Tundra was named the top light-duty full-size pickup truck in that year’s study.
Like the industry as a whole, infotainment-related problems made up the bulk of full-size pickup truck problems, according to David Amodeo, director of global automotive at J.D. Power.
“The more features these trucks have on them, the more likely there is a shift in the types of problems being reported,” Amodeo said in an email. “Infotainment software is far more sophisticated now than it was five or 10 years ago, and that has led to an uptick in infotainment-related problems.”
What’s Next?
Like other owners who reached out to us, we’re disappointed with the dealership response we received when we shared our rust concerns. After all, inspecting for rust has never been part of our list of recommendations when buying a new vehicle. After this experience, perhaps it should be.
Owners of the 2021 F-150 who receive the Initial Quality Study survey have an opportunity to make their voices heard, whether about rust or any other problems they’ve experienced. We’ll take the time to complete the survey if we get it and hope other owners do, too. Perhaps then Ford won’t see this type of rust as normal.
Related Video: 2021 Ford F-150: Review
Cars.com’s Editorial department is your source for automotive news and reviews. In line with Cars.com’s long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of Cars.com’s advertising, sales and sponsored content departments.

Mike Hanley has more than 20 years of experience reporting on the auto industry. His primary focus is new vehicles, and he's currently a Senior Road Test Editor overseeing expert car reviews and comparison tests. He previously managed Editorial content in the Cars.com Research section.
Featured stories



2025 Lincoln Navigator Review: Elephantine Elegance







