{"product_id":"x-autohaux-u-bolt-roof-box-clamps-4-pack-83mm-internal-width-fits-up-to-40mm-crossbars-with-lock-nuts","title":"X AUTOHAUX U-bolt Roof Box Clamps 4-Pack — 83mm Internal Width, Fits up to 40mm Crossbars with Lock Nuts","description":"\u003cp\u003e\u003cstrong\u003eThese X AUTOHAUX U-bolt clamps are a complete 4-piece mounting kit designed to secure most rooftop cargo boxes and carriers to crossbars up to about 40mm thick.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf you need a straightforward replacement or upgrade for the hardware that fastens your rooftop cargo box, this kit supplies iron U-bolts, rubber washers, plastic backing plates, lock nuts, and straps so you can restore or improve the connection between box and rack. The components are sized for an 83mm internal clamp width and include eight heavy lock nuts for a reliable hold; materials combine metal and engineered plastics for corrosion and wear resistance. These parts are intended for many universal carriers but are not compatible with Thule-brand racks.\u003c\/p\u003e\n\n\u003ch3\u003eWill these clamps fit my roof box and crossbar?\u003c\/h3\u003e\n\u003cp\u003eMeasure the gap and mounting points on your box and crossbar to confirm compatibility before buying. The clamp's internal width and thread spacing determine fit, and this kit is made for common aftermarket carriers rather than brand-specific systems.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eInternal clamp width: 83mm (3.27 in)\u003c\/li\u003e\n  \u003cli\u003eCenter-to-center thread spacing: 90mm (3.54 in)\u003c\/li\u003e\n  \u003cli\u003eScrew diameter: 7.5mm (0.3 in)\u003c\/li\u003e\n  \u003cli\u003eSuitable for rail\/profile thickness: up to ~40mm (1.57 in)\u003c\/li\u003e\n  \u003cli\u003eNot compatible with Thule car rack systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do these parts protect my vehicle and cargo during travel?\u003c\/h3\u003e\n\u003cp\u003eThe kit includes rubber gaskets and plastic support plates that cushion contact points and increase friction so the box stays put while driving. Properly tightened lock nuts and secure straps reduce movement and minimize the risk of abrasion or scratches to roof paint and box finish.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRubber washers absorb vibration and protect paint\u003c\/li\u003e\n  \u003cli\u003ePlastic backing plates distribute clamping force evenly\u003c\/li\u003e\n  \u003cli\u003eHeavy lock nuts resist loosening under road stress\u003c\/li\u003e\n  \u003cli\u003eIncluded straps help hold the box during installation and transit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials are used and how durable are they?\u003c\/h3\u003e\n\u003cp\u003eComponents blend iron fasteners with plastic support parts and rubber seals to balance strength and corrosion resistance. The iron bolts provide load-bearing capacity while the plastic and rubber resist wear, temperature changes, and surface damage during repeated use.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIron bolts for structural strength and rigidity\u003c\/li\u003e\n  \u003cli\u003ePlastic boards for impact distribution and anti-scratch protection\u003c\/li\u003e\n  \u003cli\u003eRubber gaskets for vibration damping and grip\u003c\/li\u003e\n  \u003cli\u003eLock nuts designed for secure fastening under load\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow easy is installation and what comes in the package?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward with basic tools; parts are sized for common aftermarket boxes and mounting holes. The kit contains everything needed to replace worn or missing fasteners so you can reattach your rooftop carrier without searching for multiple components.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIncluded: 4 iron U-bolts, 4 rubber washers, 4 plastic backing plates\u003c\/li\u003e\n  \u003cli\u003ePlus: 8 heavy lock nuts, 2 straps, 1 black sticker for alignment\u003c\/li\u003e\n  \u003cli\u003eSmall, lightweight components for easy storage when not installed\u003c\/li\u003e\n  \u003cli\u003eCheck your box measurements and any fitting guides or videos before starting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This X AUTOHAUX clamp kit is aimed at vehicle owners who use universal rooftop cargo boxes and need reliable replacement hardware—especially those with non-Thule crossbars up to 40mm thick. It's suitable for DIYers restoring a carrier, renters who bought a used box missing fasteners, and anyone wanting a compact, durable set of mounting parts to secure gear for road trips and everyday hauling. Always confirm measurements and compatibility with your box and crossbar before purchase.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Are these clamps compatible with Thule roof racks?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No, this kit is not compatible with Thule systems; measure your crossbar to confirm fit instead.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What maximum crossbar thickness will these clamps fit?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: They fit crossbars up to approximately 40mm (1.57 in) thick; check your profile thickness before buying.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"X AUTOHAUX","offers":[{"title":"Default Title","offer_id":48085355790494,"sku":"B09Q5KR3QH","price":35.9,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/x-autoHaux-front-packaging-view_513fbe83-f6ac-4be4-8278-523028a622ca.jpg?v=1785870075","url":"https:\/\/northtrailauto.ca\/products\/x-autohaux-u-bolt-roof-box-clamps-4-pack-83mm-internal-width-fits-up-to-40mm-crossbars-with-lock-nuts","provider":"North Trail Auto","version":"1.0","type":"link"}