The Excessive, Premature Rust Corrosion on the Toyota 4runner Compromises the Vehicles’ Safety

Jonathan Sharp - August 12, 2021

The 4Runner has an excellent combination for off-roading; it comes with body-on-frame construction, a rugged transmission, and a reliable engine; but the improper treatment against rust corrosion during manufacturing compromises the vehicles' safety, stability, and crash-worthiness. A recent class-action lawsuit filed in Federal Court alleges that the popular vehicles Toyota 4Runners, models manufactured between 2003 and 2009, lack adequate rust protection on the frame, which causes premature rust corrosion. As a result, the plaintiffs involved in the lawsuit sustained economic losses.

Presently, automotive manufacturers make vehicles less prone to rusting, thanks to technology and engineering advancements. The excessive rust and erosion on the Toyota 4Runner are not from normal wear, a manufacturing fault causes it.

“According to the class action complaint, the truck frames rust prematurely because they were not properly coated with anti-rust chemicals throughout the manufacturing process, leaving them exposed to corrosive factors, such as salt used to de-ice roads. It's worth noting that the 4th Generation Toyota 4Runners manufactured between 2003 and 2009 suffer from the same lack of anti-rust protection as the pickup trucks and SUVs involved in a prior $3.4 billion class-action case. What’s even worse is that the company has long been aware that frames on the Toyota 4Runner and other Toyota vehicles exhibited excessive rust corrosion due to inadequate corrosion-resistant protection. All of the frames were manufactured by the same Ohio-based Dana Holding Corporation pursuant to the same defective process”, says Gregory A. Cade, an environmental law advocate and industrial hygienist with substantial expertise and vast experience in handling claims on behalf of victims injured by a defective or dangerous product and toxic chemical exposure.

The fourth-generation models have shown significant improvements, including rear air suspension, a locking differential, descent control, and driver assistance. Most interestingly, this version borrowed the 4.7L V8 from its other successful SUVs. With so many enhancements, this was the ideal choice for both families and adventure seekers. But, the frames on the Toyota 4Runner exhibit excessive rust corrosion and perforation because they did not have adequate corrosion-resistant protection. While these features make it great for off-roading, rust, if left untreated, can spread and slowly erode the finish.

Car frames serve as a foundation for nearly all components. That is, the frame provides structural support to the vehicle's mechanical components as well as the body. To summarize, it is important to how the automobile operates and moves. Aside from the engine, a car’s frame is considered to be the most significant component because it is the foundation upon which the entire vehicle is built. In short, the major functions of the vehicle frame are to provide support and structural strength.

Damage to a vehicle's structure due to corrosion impairs its capacity to absorb the impact of a collision efficiently. A car's body structure distributes the shock force of a collision in such a way that the driver and other occupants of the vehicle are only minimally impacted. Rust-related compromises may induce early structural collapse during an accident, increasing the risk of catastrophic, even fatal damage.

A rusted-through frame can cause holes to emerge in the frame and other components to break off altogether. The metal car body construction provides a safe framework for drivers to drive in. Rust, undermines this structure by attacking the metal's integrity in unforeseen ways. For example, rust can work its way through the metal near a car's gas tank, puncturing the fuel line and causing gas to seep out when the vehicle is refueled.

According to the online automotive complaint resource, rust is the most common complaint about the 2003-2009 4Runner. The reclamations were so numerous, that the NHTSA (National Highway Traffic Safety Administration) started an official investigation.

Because rust-related damage is generally seen on the vehicle's underside, it remains undiscovered until the vehicle is intentionally inspected. Rust starts to show up after around 100,000 kilometers. Although this mileage may appear to be excessive, rust really began several miles earlier. While there is a range of precautions you can take to reduce corrosion, such as specialist coating, it is difficult to battle rust once it has commenced.

If you’re buying a used Toyota 4Runner, consider a badly rusted underframe to be a major red flag. For years, these vehicles have been plagued with notorious rust issues, so, regardless of the model you choose, be sure to check for any signs of rust and also ask for service history and recall information.

About the author:
Jonathan Sharp is the Director of Claims for the Environmental Litigation Group, P.C., a law firm located on Birmingham’s Southside, dedicated to providing high-quality legal representation to clients seriously injured by a defective product, exposure to asbestos, paraquat, toxins at military bases, and PFAS contamination from the use of AFFF.