If you plan on inspecting a car frame, there are certain steps you will need to take. First, you will want to make sure that the car is on a level surface. Once the car is level, you will want to visually inspect the frame for any damage. If there is any visible damage, you will want to use a measuring tape to see how deep and wide the damage is. If the damage looks severe, it is best to consult with a professional before continuing.
Next, you will want to feel along the frame for any bumps or dents. Again, if there is any severe damage, it is best to consult with a professional. Once you have inspected the frame visually and by feel, you will want to use a flashlight to look inside of the frame rails. You are looking for rust or corrosion inside of the rails. Rust or corrosion can weaken the integrity of the frame and cause problems down the road.
If everything looks good so far, your next step is to check all of the welds on the frame. You are looking for cracks or breaks in the welds. If any are found, it is best to consult with a professional before proceeding further.