{"product_id":"yukon-steel-full-spool-ford-9in-40-spline-axles","title":"Yukon Ford 9\" Steel Full Spool – 40 Spline","description":"\u003cp\u003eThe \u003cstrong\u003eYukon Ford 9\" Steel Full Spool\u003c\/strong\u003e provides permanent axle lockup for dedicated off-road, rock crawling, mud racing, drag racing, and competition vehicles. Unlike a conventional differential or automatic locker, a full spool mechanically connects both axle shafts so equal torque is delivered to both wheels at all times.\u003c\/p\u003e\n\u003cp\u003eManufactured from heat-treated 8620 steel, this spool is built to handle the shock loads created by high horsepower, aggressive launches, oversized tires, and severe off-road use. Designed specifically for Ford 9\" differentials using 40-spline axle shafts, it replaces the factory differential carrier with a simple, durable traction solution for vehicles where maximum strength and consistent wheel speed are more important than street-driving manners.\u003c\/p\u003e\n\u003ch4\u003eIncludes:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e(1) Yukon Ford 9\" Steel Full Spool\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Designed for 40-spline axle shafts. Not recommended for street-driven vehicles.\u003c\/p\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary class=\"details__header\"\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" fill=\"none\" viewbox=\"0 0 14 14\" width=\"14\" height=\"14\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ctable class=\"custom-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eYukon Gear \u0026amp; Axle\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eYP FSF9-40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eFull Differential Spool\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDifferential Application\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpline Count\u003c\/td\u003e\n\u003ctd\u003e40 Spline\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003e8620 Heat-Treated Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTraction Type\u003c\/td\u003e\n\u003ctd\u003ePermanent 100% Axle Lockup\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCarrier Replacement\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended Use\u003c\/td\u003e\n\u003ctd\u003eRacing and Dedicated Off-Road Applications\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStreet Use\u003c\/td\u003e\n\u003ctd\u003eNot Recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003eSold Individually\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary class=\"details__header\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" fill=\"none\" viewbox=\"0 0 14 14\" width=\"14\" height=\"14\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ctable class=\"custom-specs-table\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eYear Range\u003c\/th\u003e\n\u003cth\u003eDifferential\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eBronco\u003c\/td\u003e\n\u003ctd\u003e1966–1986\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eE-100 \/ E-150 \/ E-200 \/ E-250 Econoline\u003c\/td\u003e\n\u003ctd\u003e1969–1980\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eF-100 \/ F-150\u003c\/td\u003e\n\u003ctd\u003e1957–1987\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eFairlane\u003c\/td\u003e\n\u003ctd\u003e1957–1970\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eFalcon\u003c\/td\u003e\n\u003ctd\u003e1960–1970\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eGalaxie \/ Galaxie 500\u003c\/td\u003e\n\u003ctd\u003e1959–1974\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eGran Torino\u003c\/td\u003e\n\u003ctd\u003e1972–1976\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eGranada\u003c\/td\u003e\n\u003ctd\u003e1975–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eLTD\u003c\/td\u003e\n\u003ctd\u003e1965–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eMaverick\u003c\/td\u003e\n\u003ctd\u003e1970–1977\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eMustang\u003c\/td\u003e\n\u003ctd\u003e1965–1973\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eRanchero\u003c\/td\u003e\n\u003ctd\u003e1957–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFord\u003c\/td\u003e\n\u003ctd\u003eThunderbird\u003c\/td\u003e\n\u003ctd\u003e1955–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLincoln\u003c\/td\u003e\n\u003ctd\u003eContinental\u003c\/td\u003e\n\u003ctd\u003e1958–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLincoln\u003c\/td\u003e\n\u003ctd\u003eMark III\u003c\/td\u003e\n\u003ctd\u003e1968–1971\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003eComet\u003c\/td\u003e\n\u003ctd\u003e1964–1977\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003eCougar\u003c\/td\u003e\n\u003ctd\u003e1967–1979\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003eGrand Marquis\u003c\/td\u003e\n\u003ctd\u003e1975–1980\u003c\/td\u003e\n\u003ctd\u003eFord 9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eFitment Notes:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFits Ford 9\" differentials configured for 40-spline axle shafts.\u003c\/li\u003e\n\u003cli\u003eReplaces the differential carrier assembly.\u003c\/li\u003e\n\u003cli\u003eCompatible with many aftermarket Ford 9\" third members.\u003c\/li\u003e\n\u003cli\u003eVehicle fitment alone does not confirm compatibility; the axle must be equipped with a Ford 9\" differential and 40-spline shafts.\u003c\/li\u003e\n\u003cli\u003eVerify spline count, carrier configuration, bearing requirements, and third-member setup before ordering.\u003c\/li\u003e\n\u003cli\u003eProfessional differential setup is recommended.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary class=\"details__header\"\u003e\u003cstrong\u003eFAQ\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" fill=\"none\" viewbox=\"0 0 14 14\" width=\"14\" height=\"14\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ch3\u003eWhat is a full spool?\u003c\/h3\u003e\n\u003cp\u003eA full spool replaces the differential carrier and permanently connects both axle shafts. This eliminates differential action and sends equal torque to both wheels at all times.\u003c\/p\u003e\n\u003ch3\u003eIs a full spool stronger than a locker?\u003c\/h3\u003e\n\u003cp\u003eA spool contains no internal locking mechanisms or moving differential components, making it a simple and highly durable option for extreme racing and off-road applications.\u003c\/p\u003e\n\u003ch3\u003eCan this spool be used on the street?\u003c\/h3\u003e\n\u003cp\u003eStreet use is not recommended. Because both rear wheels remain locked together, the tires must scrub during turns, which increases tire wear and negatively affects handling on pavement.\u003c\/p\u003e\n\u003ch3\u003eWhat axle shafts are required?\u003c\/h3\u003e\n\u003cp\u003eThis spool is designed specifically for Ford 9\" differentials using 40-spline axle shafts. It will not fit lower-spline-count axle shafts.\u003c\/p\u003e\n\u003ch3\u003eIs a spool a good choice for rock crawling?\u003c\/h3\u003e\n\u003cp\u003eYes, for dedicated off-road builds. A spool provides constant traction and eliminates the possibility of a locker disengaging or failing under load. It is commonly used in competition crawlers, rock bouncers, mud trucks, and drag racing vehicles.\u003c\/p\u003e\n\u003ch3\u003eDoes a spool affect turning?\u003c\/h3\u003e\n\u003cp\u003eYes. Since both axle shafts rotate at the same speed, the inside tire cannot slow down during a turn. This causes tire scrub and increases stress on axle shafts, tires, and other drivetrain components when operating on high-traction surfaces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e","brand":"Yukon Gear \u0026 Axle","offers":[{"title":"Default Title","offer_id":57726158078118,"sku":"YP FSF9-40","price":245.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8394\/6406\/files\/3644c0ab66d408828dc56020a45f6237.jpg?v=1792610934","url":"https:\/\/wideopendesign.com\/products\/yukon-steel-full-spool-ford-9in-40-spline-axles","provider":"Wide Open Design, Inc.","version":"1.0","type":"link"}