With the sheer number of safety recalls coming out of Ford over the last few years, it can be tough to know what recalls are very serious, and which ones you should get done but might not be front of mind. The NHTSA and Ford's safety and regulatory affairs team will tell you they're all important, but this one seems like it should be top of the list.The latest recall affects 2018-2022 Ford Expedition and Lincoln Navigator SUVs... a lot of them. These big SUVs have seat belts that could get stuck or even pretension prematurely. Seat belts Could Tighten Down Without A Crash Ford In recall documents filed with the NHTSA, Ford describes that on some of the affected models, the front seat belt retractor pretensioners could deploy inadvertently while the engine is on. If a pretensioner fires, the seat belt will retract rapidly and then lock in position.A sudden deployment of the pretensioner can "cause occupant injury due to rapid seatbelt retraction." A locked belt after the deployment won't hold the driver or front passenger in place. Depending on the position when the pretensioner fired, the seat belts may be completely unusable. A Wider Scope From A Previous Recall There are 419,967 units covered under the recall, spread across both the Ford and Lincoln versions of the three-row SUV. Around 78,000 are Lincolns, and the rest are Fords, all built at the same factory. If the recall sounds familiar, it is because Ford has recalled a similar range of vehicles before, in 2024 and in 2025. That covered 2018-2020 vehicles. The latest recall widens the range.Letters to owners should go in the mail on June 8, but there won't be a fix ready at that time. Notification about the fix is set for August 31, at which point there should be replacement pretensioners available at dealers.A seat belt pretensioner is a safety device for the belt that includes a propellant that can yank the belt tight in an instant. It's designed to keep you in place in a crash even if the belt is loose, which reduces the risk of injury. If it fires randomly, then the risk of an injury is higher, along with the risk that you won't wear the belt after it locks in place. This Recall Expands Two Older Ones Ford Previous recalls addressed potentially corroded pins in the system that could cause inadvertent firing of the seat pretensioners. When those recalls were issued, Ford said it still didn't have a root cause. Since then, Ford engineers have found that it has only happened in pretensioners with a specific combination of propellant and stabilizer. In February 2022, Ford's supplier changed the combination and the issue disappeared.Ford learned that it was the early propellant that was degrading and causing the corrosion. Newer belts, with a different combination of chemicals, didn't have the same problem.The part will be replaced under recall, even if you're out of warranty. If owners have paid to have the parts replaced before the recall, they can contact Ford regarding reimbursement. If you can't drive your vehicle without properly wearing the seat belt, you shouldn't drive it. Contact your Ford dealer for help.