{"product_id":"skf-set421-wheel-bearing-inner","title":"SKF SET421 Wheel Bearing - Inner","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eSKF SET421 is an inner wheel bearing for heavy-duty rear wheel applications that require tapered roller bearing construction. It is built for Mack trucks across a broad range of model years and supports smooth, quiet operation with a precision roller raceway profile and fine surface finish.\u003c\/p\u003e\u003cp\u003eCompatible With Mack CHU, CXU, GU7, GU8, MRU, and related models in inner rear wheel bearing applications. The SET421 part number is used for fitment verification, and SKF SET421 is also referenced by cross-number applications for the same use case.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eTapered roller bearing set construction for wheel-end service.\u003c\/li\u003e\n\u003cli\u003eLogarithmic roller raceway profile for consistent rolling contact.\u003c\/li\u003e\n\u003cli\u003eUltra-smooth surface finish for reduced operating noise.\u003c\/li\u003e\n\u003cli\u003eDimensions: 3.250 in inside diameter, 5.250 in outside diameter, 1.562 in width.\u003c\/li\u003e\n\u003cli\u003eFits Mack heavy-duty trucks with S440 GAWR 44k lb rear wheel inner bearing applications.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Description\u003c\/h2\u003e\u003cp\u003eSKF SET421 is engineered as an inner wheel bearing for rear wheel service on Mack commercial trucks. Fitment includes 1998-2018 Mack CHU, CXU, GU7, GU8, LR600, MRU, TerraPro, Granite, TD700, Vision, CTP, CV, CL, CT, CXN, CXP, MR, DM, CX, and DMM applications with S440 GAWR 44k lb notes. The bearing set uses tapered roller geometry to handle wheel-end loads while maintaining smooth rotation. SKF SET421 is a direct reference for buyers searching by part number or by Mack wheel bearing fitment.\u003c\/p\u003e\u003cp\u003eThis part cross-references Bosch 16488 for the same application.\u003c\/p\u003e\u003ch2\u003eWhat It Is Used For\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eReplacing a worn inner wheel bearing in rear wheel service.\u003c\/li\u003e\n\u003cli\u003eAddressing wheel-end noise during operation.\u003c\/li\u003e\n\u003cli\u003eRestoring proper rolling support in heavy-duty axle assemblies.\u003c\/li\u003e\n\u003cli\u003eCorrecting looseness or roughness at the wheel end.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eVerify axle and hub specifications against the listed fitment notes before installation. Confirm the bearing dimensions and application details match the existing component, especially on Mack trucks with S440 GAWR 44k lb rear wheel inner bearing requirements. Clean and inspect the hub and related surfaces during service to help ensure proper bearing seating.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eSKF states that its products are manufactured to high quality standards for long service life and safety. The SET421 bearing set is part of SKF's tapered roller bearing line, which is used across a wide range of applications.\u003c\/p\u003e","brand":"SKF","offers":[{"title":"Default Title","offer_id":53396521615541,"sku":"BCNB-SET421","price":108.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/CR_SET421_Fro.jpg?v=1790664972","url":"https:\/\/www.partcatalog.com\/products\/skf-set421-wheel-bearing-inner","provider":"PartCatalog","version":"1.0","type":"link"}