Frame straightening sounds scary, but it’s more common than you’d think. Frames are bent in about half of auto accidents, making this a regular part of autobody repair. Here’s how a little bending, cutting and welding can bring your car back to its original shape and performance.
Collisions exert tremendous forces on your vehicle, and one way or another, those forces will reach the frame. Aside from weakening the vehicle’s structure, it also pushes parts out of place. Trying to replace body panels on a bent frame will lead to fitment problems, and there will be underlying mechanical issues. For example, if the axles aren’t lined up correctly, the vehicle will “crab,” going down the road at an angle to keep all four wheels turning in the same direction.
Modern cars have frame rail sections built to bend in accidents. This “crumple zone” absorbs some of the impact force before it can reach the cabin. As a result, damage to the front and rear of the frame is far more common than damage to the straighter, stronger sections under the cabin.
What is a Frame?
Body-on-frame: The body of the car bolts onto a separate frame
Unibody: The frame, floor pan and sometimes the aprons and rear supports are built as a single unit. This makes the vehicle lighter and lower to the ground. Most modern cars, mini-vans and crossovers use unibody construction.
Spaceframe: The frame stretches across the entire vehicle from the floor pan to the roof. This design is lightweight, and it’s great for occupant safety, but it’s also expensive to produce. This design is used in some high-end luxury cars.