{"product_id":"skf-39139-engine-crankshaft-seal-rear","title":"SKF 39139 Engine Crankshaft Seal - Rear","description":"\u003ch2\u003eEngine Crankshaft Seal Overview\u003c\/h2\u003e\u003cp\u003eSKF 39139 is an engine crankshaft seal built for rear applications on select BMW models. It uses a nitrile sealing surface and application-specific dimensions to help maintain proper sealing at the crankshaft interface.\u003c\/p\u003e\u003cp\u003eFits select BMW 540i, M5, X5, Z8, 740i, 740iL, 750iL, 840Ci, 850Ci, 530i, 850CSi, and 850i rear applications. Part number 39139 is a direct reference for buyers searching for a rear crankshaft seal for BMW engine sealing service.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eNitrile sealing surface for engine oil sealing applications.\u003c\/li\u003e\n\u003cli\u003eSpecified width, outside diameter, and shaft diameter for application matching.\u003c\/li\u003e\n\u003cli\u003eRear crankshaft seal design for select BMW engines.\u003c\/li\u003e\n\u003cli\u003eSKF sealing engineering backed by long-running OE-style manufacturing practices.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Description\u003c\/h2\u003e\u003cp\u003eSKF 39139 is an engine crankshaft seal engineered for rear installation points on a wide range of BMW applications. The seal is specified with a 0.472 width, 4.929 outside diameter, and 3.937 shaft diameter, helping ensure the part matches the intended crankshaft sealing interface. The nitrile sealing surface is selected for engine oil sealing performance in the operating environment of the application.\u003c\/p\u003e\u003cp\u003eSKF has a long history in seal development, including early integrated shaft seal design and continued refinement of bonding and material selection. For buyers servicing BMW 540i, BMW 740i, BMW 740iL, or related models, part number 39139 provides a focused replacement option for rear crankshaft sealing service. This part cross-references Monroe Shocks \u0026amp; Struts (e.g., 145839139, 975939139) for the same application.\u003c\/p\u003e\u003ch2\u003eCommon Problems This Part Addresses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eOil seepage at the rear crankshaft sealing area.\u003c\/li\u003e\n\u003cli\u003eContamination entering the engine sealing interface.\u003c\/li\u003e\n\u003cli\u003eSeal wear from age, heat, and normal engine operation.\u003c\/li\u003e\n\u003cli\u003eLoss of proper crankshaft oil retention during service intervals.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eConfirm shaft diameter and seal dimensions before installation. Inspect the crankshaft sealing surface for wear, scoring, or contamination before fitting the new seal. Clean the sealing area thoroughly and follow the vehicle service procedure for correct placement and alignment. For BMW rear crankshaft seal service, verify the application against the listed fitment before beginning work.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eSKF designs and manufactures seals to specific application requirements using premium materials and established bonding techniques. The brand’s seal engineering heritage and manufacturing standards support consistent sealing performance and long service life.\u003c\/p\u003e","brand":"SKF","offers":[{"title":"Default Title","offer_id":53512163590325,"sku":"BCNB-39139","price":24.34,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/CR_39139_Fro.jpg?v=1791874006","url":"https:\/\/www.partcatalog.com\/products\/skf-39139-engine-crankshaft-seal-rear","provider":"PartCatalog","version":"1.0","type":"link"}