{"product_id":"one-piece-billet-steel-crank-hub","title":"One-Piece Billet Steel Crank Hub","description":"The MMR Performance MMR20-1001 is a one-piece crank hub upgrade kit engineered to eliminate a well-documented failure point in BMW's S55 and N55 engines. The original three-piece crank hub relies on friction surfaces that can slip under load, potentially causing timing misalignment and severe engine damage. This MMR upgrade replaces the stock design with a fully integrated, one-piece billet construction made from EN36 steel, which is then case-hardened to 0.75mm for enhanced durability and wear resistance.\n\nThis direct-fit solution ensures consistent crankshaft timing, significantly improving long-term engine reliability for both stock and high-performance applications. The kit includes a new crank bolt to guarantee proper installation and clamping force, providing a robust replacement for the OE component. For an additional layer of security against crank bolt loosening from engine harmonics or vibration, an optional capture plate is available.\n\nThis upgrade is recommended for both stock and tuned engines. For builds exceeding standard high-horsepower levels, MMR suggests considering their upgraded 4-pin crank hub option. Professional installation is required for this component. The MMR Performance crank hub is designed and tested in the United Kingdom and comes with a 1-year manufacturer warranty against defects in materials and workmanship.","brand":"MMR Performance","offers":[{"title":"Default Title","offer_id":52689254580536,"sku":"MMR20-1001","price":730.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/687390534.webp?v=1784904131","url":"https:\/\/store.motormia.co\/products\/one-piece-billet-steel-crank-hub","provider":"MOTORMIA","version":"1.0","type":"link"}