Frame and Structural Repair
Frame and Structural Repair
This domain tests structural straightening and replacement on unibody and frame vehicles. Expect measuring systems, anchoring, pulling, stress relieving, sectioning, structural welding, corrosion protection, and OEM repair procedures. The exam emphasises restoring the collision energy path, not just making the vehicle look straight.
Core rules
- Establish a baseline with a 3D measuring system at OEM control points; record before, during, and after pulls.
- Anchor the vehicle at specified locations before pulling. Pulling without proper anchoring can distort other areas.
- Use multiple pulls in the direction of the original impact; avoid single heavy pulls that overstretch metal.
- Stress relieving may be required after straightening; use only OEM-approved methods and heat limits.
- Replace rather than straighten kinked, torn, or severely deformed structural parts. Section only at OEM-listed locations and duplicate weld counts and types.
- Restore corrosion protection: e-coat, weld-through primer, seam sealer, cavity wax, and undercoating.
- Verify suspension, driveline, and ADAS mounting points after structural work.
Worked example
A front-end collision leaves the left upper rail swayed and the apron buckled. The technician anchors the vehicle, measures control points, and pulls the rail in stages while monitoring the door gap and strut tower. Reasoning: a single pull could tear the rail or move the strut tower. After the rail is within tolerance, the technician checks for kinks; if the rail is kinked or the OEM prohibits repair, it is sectioned or replaced at specified locations. Finally, seam sealer and cavity wax are restored.
Traps
- Pulling without anchoring or measuring.
- Straightening a kinked rail because it looks close enough.
- Using heat on structural steel without OEM approval.
- Skipping seam sealer or cavity wax.
- Ignoring suspension or ADAS mounting point damage.
- Sectioning at a convenient point rather than an OEM-approved location.