# Frame and Structural Repair for Large Vehicles > Frame and structural repair restores a vehicle's geometry after impact, fatigue or overload. Work runs $750 to $20,000 across 5 to 80 hours and covers frame straightening on a rack, chassis alignment, subframe and outrigger repair, unibody straightening on van chassis, and written structural damage assessment. All welding is performed in shop. Source: https://ocrv.biz/services/frame-structural-repair/ Business: OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887. (949) 799-3387. Serving Tustin, California. Ballpark range: $750 to $20,000. Posted rates at https://ocrv.biz/prices/ ## How do you know a frame is actually bent? By measurement against control points, not by looking at it. Frames are bent in three dimensions and the human eye is poor at detecting deflection along the length of a 40 foot rail. What the eye does catch is the symptom: a vehicle that dog tracks down the road, uneven tire wear across an axle, a slide that binds on one corner, a compartment door that used to close. Control points are known dimensions from the manufacturer between fixed reference locations on the chassis: spring hanger centers, crossmember bosses, suspension mounting points, body mount locations. Measured diagonals across those points reveal twist and diamond. Measured heights reveal sag and sway. A frame within specification measures within tolerance on all three. Three deflection types show up in practice. Sag is vertical droop, usually from overload or from a long slow bend. Sway is lateral, usually from side impact. Twist is rotational, usually from a single corner being loaded hard, and it is the one owners notice as a vehicle that leans and steers oddly at the same time. Trailer frames fail differently again. A tandem axle trailer frame cracks at the spring hanger welds and at the A-frame to main rail junction, because those are the points that see the most cycles. Those cracks propagate from a weld toe and they get longer every trip. ## What does anchoring and pulling involve? Anchoring is the half of the job most people never think about. Before force is applied to the damaged section, the undamaged section has to be held absolutely still. On a truck or coach chassis that means clamping the frame rail flanges with purpose-built chassis clamps, often at four or more points, tied to the rack floor anchors. If the anchoring is inadequate, the pull moves the whole vehicle instead of the bent section, or worse, transfers the deformation into a section that was previously straight. That is how a repairable frame becomes a scrapped frame. Force is applied in stages through hydraulic rams and pulling towers, with the structure re-measured between each stage. Steel that has yielded springs back part way, so the target is over-pulled slightly and allowed to settle onto specification. Heat is used sparingly and only where the material and the manufacturer allow it, because heating high strength steel past its tempering range permanently reduces its strength whether the shape looks right afterward or not. Sectioning, which means cutting out damaged rail and welding in replacement material, is a last resort and is done only at manufacturer-approved locations with the specified joint design. A butt weld in the middle of a rail flange under a slide room is a future failure. ## Which sub services live under this line? - [Frame Straightening](/services/frame-structural-repair/frame-straightening/): rack work on bent rails, sag, sway and twist correction with measurement between pulls. - [Chassis Repair and Alignment](/services/frame-structural-repair/chassis-repair-alignment/): suspension mounting points, axle alignment, and the chassis lube and basic service band at $300 to $1,200. - [Subframe Repair](/services/frame-structural-repair/subframe-repair/): outriggers, crossmembers, slide room support structure and the brackets that tie a coach body to its chassis. - [Unibody Straightening](/services/frame-structural-repair/unibody-straightening/): van chassis where the body is the structure, which is a different anchoring and measuring problem entirely. - [Structural Damage Assessment](/services/frame-structural-repair/structural-damage-assessment/): written evaluation with measurements, at the cosmetic and structural body inspection band of $250 to $600 across 1 to 3 hours. Sibling lines under [collision and structural services](/services/collision-structural/) are [collision repair](/services/collision-repair/) and [fiberglass repair](/services/fiberglass-repair/). Structural work almost always hands off to one or both once the geometry is corrected. ## Why do coach bodies need separate structural attention? Because the house and the chassis are two structures bolted together, and they can be damaged independently. Correcting the chassis does not correct the house. A motorhome house is a framed box: aluminum tube or wood framing, laminated panels bonded to it, tied down to the chassis at body mount brackets. When the chassis twists, the mounts transmit that twist into the house framing, which yields in its own way. The visible result is a slide opening that is no longer rectangular, a roof line that has a wave in it, or interior cabinetry pulling away from a wall. Correcting the house means opening it. Interior panels come off, framing is inspected joint by joint, damaged tube is cut and replaced with matching section, and the panel bond is restored before anything gets skinned back over. Framing repair inside a coach is welding, and it is welding in a confined space full of wiring, plumbing and insulation, which is why the labor band reaches 80 hours. Trailer frames are a related but distinct problem. Structural welding on a trailer runs the same $750 to $20,000 band, but the failure modes are fatigue cracks at spring hangers, bent tongues from jackknifing, and corroded crossmembers on units that lived near the coast. See the [posted price sheet](/prices/) for the full band. ## Questions ### Can a bent trailer tongue be straightened or does it need replacing? It depends on whether the metal tore and where the bend sits relative to the coupler. A gentle bend in sound material can be pulled and reinforced. A kinked A-frame with a crack at the weld toe gets sectioned and replaced, because pulling a cracked member just opens the crack further. ### Is it safe to keep towing a trailer with a cracked frame weld? No. A crack at a spring hanger or an A-frame junction grows every mile because the joint sees full cyclic loading. Cracks propagate from the weld toe and the failure when it comes is sudden. Get it measured and repaired before it is towed again. ### How much does frame straightening cost on a motorhome? Frame and structural welding and repair runs $750 to $20,000 across 5 to 80 hours. The spread reflects how much has to come apart to reach the damage and whether the coach body framing moved along with the chassis, which on any significant impact it usually did. ### Do you provide written structural assessments for insurance? Yes. Structural damage assessment produces a written report with control point measurements against specification, photographs and a repair scope. That is the document a carrier needs to decide between repair and total loss, and it runs $250 to $600 across 1 to 3 hours. ## Related - [Collision and Structural Services](https://ocrv.biz/services/collision-structural/) - [Collision Repair](https://ocrv.biz/services/collision-repair/) - [Fiberglass Repair](https://ocrv.biz/services/fiberglass-repair/) - [Frame Straightening](https://ocrv.biz/services/frame-structural-repair/frame-straightening/) - [Chassis Repair and Alignment](https://ocrv.biz/services/frame-structural-repair/chassis-repair-alignment/) - [Subframe Repair](https://ocrv.biz/services/frame-structural-repair/subframe-repair/) - [Unibody Straightening](https://ocrv.biz/services/frame-structural-repair/unibody-straightening/) - [Structural Damage Assessment](https://ocrv.biz/services/frame-structural-repair/structural-damage-assessment/) - [Prices and Posted Rates](https://ocrv.biz/prices/)