The only way to straighten an automobile frame is to use a frame machine. This machine is only available at certain professional auto body shops. The machine uses a mechanism with hydraulics, as it needs a lot of power to put the frame back to factory specifications.
To use the machine, the mechanic drives the vehicle up onto a platform and bolts it into place with clamps. Once the vehicle is unable to move, the mechanic places chains onto the frame depending on where the straightening is necessary. With the chains in place, the hydraulic equipment begins to slowly increase tension using hydraulics. There is an electronic measurement system that measures and verifies that the adjustments are correct and stops the machine when the frame is back to factory specifications.
The actual machine consists of a platform that is large enough to hold an SUV, car or pickup. There are two to three towers that move 360 degrees along the platform to work on different areas of the frame. Modern machines use computers with line-of-sight sensors and lasers to assess a frame and then decide how much damage is present. This information determines if a car is repairable and offers an estimate of how long the repair takes. The equipment also helps to ensure the repair is correct and accurate.