# Subframe Repair: Cost, Hours and Process in Hacienda Heights Subframe repair addresses the secondary structure the coach builder adds on top of the chassis: floor perimeter rails, slide room support boxes, generator and tank cradles, and the cantilevered extensions behind the rear axle. It is where impact and long term load damage most often meet on a motorhome. ## Specifications - Price band: $2,500 to $14,000 - Shop hours: 12 to 60 hours - Turnaround tier: Structural - Insurance billable: yes - Parts lead time: 5 to 20 business days for tube and Lippert sections, 4 to 10 weeks for builder specific cradles - OEM brands: Lippert, Car-O-Liner, Spartan Chassis, Freightliner Custom Chassis, Chief ## What a subframe is and why builders add one A motorhome chassis arrives at the coach builder as rails, a drivetrain and a cowl. Everything the floor plan needs beyond that gets built on top: a perimeter rail defining the floor outline, transverse members carrying loads out to it, boxes that support the slide rooms, cradles for tanks and generator, and often an extension cantilevered out behind the rear axle to reach the rear cap. That secondary structure is usually welded aluminum or steel tube, lighter than the chassis it sits on and engineered to a specific load case. It carries the coach, not the road, which is why it is often the first thing to yield in an impact even when the chassis rails read inside tolerance. It is also the structure most affected by how the coach has been used. A rear extension carrying a heavy cargo tray for ten years is already working near its design limit, and an impact that a factory fresh coach would shrug off will crack it. ## The slide room box, the most common finding Slide rooms are heavy, hung off a box structure at the floor line, and cantilevered out when extended. That combination concentrates load exactly where a side impact lands. A strike to the slide side of a coach very often leaves the room looking fine and the box under it distorted a fraction of an inch, which is enough to bind the mechanism. The symptom owners report is a slide that got harder to run or that scrubs its seal on one side. The temptation is to service the mechanism. Servicing a mechanism whose opening has moved is money spent on the wrong component, and it is one of the most common wasted repairs we see. We measure the opening diagonals and the box plane before touching the slide hardware. If the opening reads out of square, the box gets corrected first, and only then does the mechanism get evaluated on a structure that will let it work. - Slide opening diagonals measured before any mechanism work - Box plane checked for twist and drop at the outboard edge - Distorted tube sectioned and replaced with matching profile - Load path reinforced where the original design was marginal - Slide mechanism evaluated only after the opening reads square ## Rear extensions, sag and the cargo tray problem The cantilever behind the rear axle is the other frequent finding. It carries the rear cap, often a tank, sometimes a generator and frequently an owner installed cargo tray or a hitch receiver that the builder never designed for. Sag there presents as a low rear bumper, a rear cap that has dropped relative to the sidewall line, and cracked sealant along the rear cap seam. When an impact adds to that, the extension can fold rather than bend, and repair means sectioning and adding the load path that should have been there. We will reinforce an extension beyond original specification where the history shows the original was marginal, and we will say so in writing. Putting a coach back to exactly the design that already failed once is a repair with a known end date. ## Hours, cost and the insurance boundary Labor runs 12 to 60 hours at the posted body and paint rate of $210 per hour. Access is the biggest variable. A floor rail reachable from underneath is straightforward. The same rail behind a tank, a generator, a wiring run and a coroplast underbelly means removing all of those first, and reinstalling them after. The insurance boundary matters more here than on most collision work. Impact damage to a subframe is a covered cause. Fatigue cracking, corrosion and overload sag are generally not, and a real subframe often has both at once. We photograph and describe them separately so the adjuster can see which is which, and so you can decide whether to have the non covered portion repaired at the same time. Doing both while the underbelly is open costs far less than doing them in two visits. ## Not included - We do not perform subframe work at a customer location. The structure requires lift access and anchoring. - Floor covering and interior finish reinstallation is quoted as interior work, separately. - Corrosion driven subframe failure with no impact event is usually not an insurance covered cause. ## Questions **What is the subframe on a motorhome?** It is the secondary structure the coach builder welds on top of the bare chassis: the floor perimeter rail, the transverse members, the boxes supporting slide rooms, tank and generator cradles, and any extension cantilevered behind the rear axle. It carries the house portion of the coach. It is lighter than the chassis and frequently yields in an impact that leaves the chassis rails in tolerance. **Why is my slide sagging or binding after an impact?** Usually because the box structure under the opening moved, not because the mechanism failed. A fraction of an inch of distortion at the floor line is enough to bind a room and to compress a seal unevenly. We measure the opening diagonals before touching hardware, because servicing a mechanism inside an out of square opening is money spent on the wrong part. **How much does subframe repair cost?** The band on this page covers 12 to 60 hours at $210 plus materials. Access drives it more than the repair does. An exposed floor rail is near the bottom. A rail behind tanks, a generator, wiring and an intact coroplast underbelly is near the top, because everything in front of it has to come out and go back. **Will insurance pay for subframe damage?** Impact caused damage, generally yes. Fatigue cracking, corrosion and overload sag are normally treated as maintenance and are not covered. Real subframes often show both at the same time, so we document them as separate findings with photographs, which lets the adjuster approve what is covered without the whole file getting questioned. **Can you reinforce the subframe beyond the original design?** Yes, and on rear extensions we frequently recommend it. If the original load path already sagged under normal use, restoring it exactly means the repair has a known expiration. We add material and triangulation where the history shows the design was marginal, document what was changed, and keep the added reinforcement as a separate line item on the invoice. --- Source: https://ocrv.club/rv-collision-repair/subframe-repair OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887 Phone (949) 799-3387. Email info@ocrvcenter.com. Serving Hacienda Heights and the surrounding area. 18.4 miles, 24 to 38 minutes via SR-60 west to Fullerton Rd, then south to La Palma Ave. In shop work only. All estimates are priced and credited against an authorized repair.