Sumyola Rear Main Seal Gasket Cover for GM Chevy LS Engines - Replacement Cover & Bolts, OEM Fit

Sumyola Rear Main Seal Gasket Cover & Bolts replace OEM rear main cover parts for GM Chevy LS engines, restoring a secure seal at the back of the crankcase.

This rear main seal gasket cover kit is engineered to match the fit and function of the original GM components for a long list of Chevrolet, GMC, Cadillac and related models that use LS-series engines. The kit replaces part numbers 635-518, 12633579 and 12639250 and ships with the cover and the hardware needed for installation. Sumyola combines factory production experience and certified quality control to deliver a ready-to-install replacement that helps stop leaks and maintain proper crankcase sealing when performing engine repair or rebuild work.

Which vehicles and part numbers does this cover fit?

This Sumyola rear main seal cover is made to replace the listed OEM part numbers and fits a wide range of GM vehicles that use the LS engine family. Compatibility covers many Chevrolet, GMC, Cadillac, Pontiac, Saab and Hummer models across model years noted in the product specs.

• Replaces part numbers: 635-518, 12633579, 12639250.
• Chevrolet: Avalanche, Camaro, Caprice, Colorado, Corvette, Express, Silverado, SSR, Suburban, Tahoe, Trailblazer.
• GMC: Canyon, Envoy, Savana, Sierra, Yukon.
• Also fits select Cadillac, Buick, Hummer, Pontiac and Saab models using GM LS engines.

How is the quality and what certifications back the part?

Sumyola manufactures this cover in a facility with over 16 years of production experience and follows formal quality systems. The factory holds IATF 16949:2016 certification and each unit undergoes inspection by an independent QC department before shipment.

• IATF 16949:2016 certified production standards.
• Independent quality control inspections and repeated testing per unit.
• One-year limited warranty covering manufacturing defects.

What comes in the kit and what support is available during installation?

The package includes the rear main seal gasket cover plus the bolts required for installation, prepared to match the OEM attachment points. Sumyola offers technical support from an engineering team that can help diagnose fitment questions or fault codes encountered after installation.

• Complete cover plus mounting bolts to replace the factory unit.
• Remote engineering support for installation troubleshooting and fault-code help.
• Fast VIN fitment check service—provide your VIN and Sumyola will verify fit within one business day.

Will I get a refund if the part doesn’t fit my vehicle?

Yes. If you can't confirm fitment, supply your vehicle VIN prior to purchase and Sumyola will verify compatibility within one business day. If the part is found non-applicable, the purchase will be refunded promptly.

• VIN-based compatibility verification available on request.
• Non-applicable parts are eligible for immediate refund.
• One-year warranty covers manufacturing-related failures only.

Who is this for? This rear main seal gasket cover kit is aimed at professional mechanics, automotive technicians, and experienced DIYers who are repairing or rebuilding GM LS engines and need a reliable OEM-equivalent replacement. It is particularly suited for owners of the vehicles listed in the compatibility notes who want a certified, inspected part backed by a warranty and technical support. If you need fitment assurance, provide your VIN for a confirmation before installation.