Structural adhesives can be incredibly strong when applied correctly, often providing durable bonds that rival or even surpass traditional fasteners. However, their strength depends entirely on precise application procedures. When those steps aren’t followed, the results can be disastrous — a lesson that Tesla Cybertruck owners are learning firsthand. According to recent reports, the automaker has discovered a widespread issue affecting hundreds of Cybertrucks where the glued-on LED light bar can detach from the vehicle. Due to this problem, Tesla has issued a recall affecting nearly 6,200 trucks, acknowledging that at least 600 owners have already experienced the issue.
In a new filing with the National Highway Traffic Safety Administration (NHTSA), Tesla detailed the nature of the problem. The defect involves an optional LED light bar mounted to some Cybertruck models, which isn’t attached using traditional hardware like bolts or screws. Instead, the light bar is secured with a structural adhesive, which requires a specific primer to be applied before bonding. If the wrong primer is used—or if the application process is not properly followed—the adhesive fails to bond correctly, allowing the light bar to loosen or even fly off while driving.
Tesla reported 619 warranty claims related to this issue, along with one field report potentially caused by improper adhesive application. Fortunately, the automaker says there have been no accidents or injuries resulting from the problem so far. The company’s internal investigation revealed that technicians may have accidentally mixed up two different primer products—BetaSeal and BetaPrime—during installation. Despite Tesla issuing multiple service bulletins and updates to its repair manuals, the confusion persisted across service centers, leading to recurring failures in the adhesive bond.
To correct the issue, Tesla has announced a straightforward remedy plan. Authorized service centers will inspect affected vehicles, examining the light bar to determine whether it was properly installed. If necessary, technicians will retrofit or replace the light bar, this time securing it with a mechanical attachment system in addition to adhesive tape. Essentially, this means Tesla will revert to using physical fasteners, such as bolts or brackets, to ensure a more reliable connection and prevent similar failures in the future.
As the recall is still new, detailed repair diagrams have not yet been released, and owner notifications are expected to begin the day after Christmas. In the meantime, Tesla recommends that Cybertruck owners with the optional light bar inspect their vehicles and contact a service center if they notice any looseness or detachment. The issue underscores how even advanced materials like structural adhesives require precise procedures — and how small mistakes in manufacturing can lead to large-scale recalls, even for a company as innovative as Tesla.