{"product_id":"oraevy-rear-main-seal-gasket-set-for-gm-ls-engines-bs40640-fits-4-8l-6-2l-oem-replacement","title":"ORAEVY Rear Main Seal Gasket Set for GM LS Engines — BS40640 Fits 4.8L–6.2L, OEM Replacement","description":"\u003cp\u003e\u003cstrong\u003eORAEVY BS 40640 Rear main seal gasket set is a direct-fit replacement for GM LS-series Vortec engines designed to stop crankshaft oil leaks and restore a reliable seal on 4.8L–6.2L applications.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf your Chevy, GMC or related GM vehicle with an LS-series engine is leaking oil at the rear of the crankshaft, this gasket and seal kit gives you the parts needed to reseal the rear main area. The kit replaces OEM numbers 89060436 and 12639249 and fits a wide range of GM Vortec engines — from small-block 4.8L truck units up to 6.2L performance engines — covering many Chevrolet, GMC, Cadillac and Buick models across two decades.\u003c\/p\u003e\n\n\u003ch3\u003eWhich vehicles and engines will this gasket set fit?\u003c\/h3\u003e\n\u003cp\u003eThis kit is made for GM LS-family Vortec engines found in many trucks, SUVs and passenger cars built roughly from 1999–2020. It covers common displacement variants used by Chevrolet and GMC and is compatible with both truck and SUV applications.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFits 4.8L, 5.3L, 5.7L, 6.0L and 6.2L LS engines (LS1, LS2, LS3, LS6, LQ4, LQ9 equivalents).\u003c\/li\u003e\n  \u003cli\u003eCompatible vehicles include Silverado, Sierra, Suburban, Tahoe, Yukon, Avalanche, Trailblazer, Envoy, Escalade, Camaro and many more.\u003c\/li\u003e\n  \u003cli\u003eReplaces OEM part numbers 89060436 and 12639249 (BS 40640).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat comes in the package and what quality can I expect?\u003c\/h3\u003e\n\u003cp\u003eThe ORAEVY set arrives with the rear main gasket and seal components plus simple installation aids. Parts are manufactured to meet or exceed typical equipment specifications and are engineered to resist oil, heat and crankcase pressure over time.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIncludes one full rear main gasket\/seal set, a pair of installation gloves and a small cleaning brush.\u003c\/li\u003e\n  \u003cli\u003eMaterials designed to withstand high temperatures and exposure to engine oil.\u003c\/li\u003e\n  \u003cli\u003e12-month limited warranty and seller support for fitment or product concerns.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow should I prepare and install the rear main seal gasket set?\u003c\/h3\u003e\n\u003cp\u003eInstalling a rear main seal typically requires removing the transmission or transaxle to access the crank flange. Proper cleaning and inspection of mating surfaces prevents repeat leaks; follow vehicle service manual torque specs for reassembly.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDrain oil and remove transmission to access the rear main area safely.\u003c\/li\u003e\n  \u003cli\u003eUse the included brush and a suitable solvent to clean the crank housing and flange surfaces thoroughly.\u003c\/li\u003e\n  \u003cli\u003eInstall seal and gasket squarely; torque bolts to manufacturer specs and replace any worn fasteners or bearings as needed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this stop my oil leak permanently?\u003c\/h3\u003e\n\u003cp\u003eA correctly sized, well-installed seal and gasket can eliminate leaks caused by worn or damaged rear main seals. Long-term success depends on correct fitment, clean mating surfaces and addressing any related causes like crankshaft flange wear or excessive crankcase pressure.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplace the seal when mating surfaces are clean and damage-free for best results.\u003c\/li\u003e\n  \u003cli\u003eInspect crankshaft flange for grooves—machine or replace if required before seal installation.\u003c\/li\u003e\n  \u003cli\u003eRepair or diagnose excessive crankcase pressure sources to avoid future failure.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The ORAEVY BS 40640 rear main seal gasket set is for DIY mechanics, professional technicians and fleet maintainers working on GM LS-series V8 and V6 Vortec engines who need a cost-effective, OE-interchange replacement. It’s ideal if you’re restoring a leak-prone engine, performing a transmission service that exposes the rear main, or preparing an engine for long-term reliability.\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: Does this replace OEM part number 89060436?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, it’s an OE-interchange replacement compatible with OEM 89060436 and 12639249.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is the kit suitable for a 5.3L Silverado?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, it fits 5.3L LS engines in Silverado and many other GM models listed.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"ORAEVY","offers":[{"title":"Default Title","offer_id":55163380269399,"sku":"B08ZCDW278","price":31.74,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/oraevy-rear-main-seal-gasket-front-view.jpg?v=1790343719","url":"https:\/\/britishgarage.co.uk\/products\/oraevy-rear-main-seal-gasket-set-for-gm-ls-engines-bs40640-fits-4-8l-6-2l-oem-replacement","provider":"British Garage","version":"1.0","type":"link"}