How Frame Straightening and Measuring Works, Step by Step

Securing the car

The vehicle is lifted onto a frame machine and anchored at points designed for it so the pull moves the damaged section, not the whole car.

Measuring

Measurements compare reference points on the underbody to manufacturer data. Differences show where the structure is out and by how much.

Controlled pulls

Chains and clamps apply force in the direction opposite to the damage. Pulls are gradual and repeated.

Re-measuring

After each pull, the shop measures again. The goal is to get all points within tolerance.

Sections and replacement

Some damaged sections must be replaced per procedure instead of pulled. This is determined by the material and location.

After the pull

Bodywork, paint and mechanical checks follow, then alignment.

Why shops measure instead of eyeball

A car can look straight and still be several millimeters out. Eyeballing cannot detect those errors, but wheels and tires can. A measuring system uses electronic or mechanical gauges to compare many points on the underbody with the manufacturer's specifications.

The measurement report becomes a record. It shows how far each point was out before the repair and where it ended up.

What you can ask to see

Ask for the before and after measurement printout. It lists reference points with their specified and measured values. Differences within the manufacturer's tolerance are acceptable.

Also ask which measuring system the shop uses and whether any structural sections were replaced. If a shop cannot show measurements, ask why. Our free estimate includes a conversation about how structural damage would be handled on your car.