AUTOBABA Engine Rear Main Seal Cover Kit for GM 4.8/5.3/6.0/6.2L — Aluminum with Gasket & Bolts

AUTOBABA Engine Rear Main Seal Cover Kit with gasket and bolts replaces GM part numbers 635-518, 12633579, 12639250 for many Cadillac, Chevy, GMC, Buick and other GM-based vehicles.

This replacement rear main seal cover is designed to match OEM form and function for a secure, long-lasting seal at the back of the engine. Manufactured from corrosion-resistant aluminum and supplied with a pre-cut gasket and mounting bolts, the kit helps restore proper sealing where the crankshaft exits the block. Before ordering, confirm vehicle fitment against the included part numbers and the compatibility list to ensure an exact match for your model year and engine.

Which vehicles and engines does this rear main seal cover fit?

The kit covers a broad range of GM models across multiple brands and years, including Cadillac Escalade, GMC Sierra/Yukon, Chevy Silverado/Suburban/Tahoe, and many others using GM small- and big-block V8s. Fitment extends to 4.8L, 5.3L, 6.0L and 6.2L engine families listed in the compatibility notes. Always cross-reference your VIN, engine code, or original part number to confirm compatibility.

• Chevy: Avalanche, Camaro, Corvette, Express, Silverado, Suburban, Tahoe and more (years vary).
• GMC: Sierra, Yukon, Savana, Canyon, Envoy and other compatible models.
• Other makes: Buick, Cadillac, Hummer, Isuzu, Pontiac, Saab in specified years.
• Replaces OEM numbers: 635-518, 12633579, 12639250 — verify before purchase.

How is this cover kit built and what materials are used?

Constructed from high-grade aluminum, the cover is machined to meet OEM-like tolerances for a stable fit and improved corrosion resistance. The package includes a precisely cut gasket and hardware so you have the required components for installation. The aluminum body reduces the risk of rust compared with some stamped-steel aftermarket alternatives, while the gasket provides the sealing surface between cover and block.

• High-quality aluminum housing for corrosion resistance.
• Pre-cut gasket matched to the cover’s sealing flange.
• Included mounting bolts to replace worn fasteners.
• Engineered to align with factory bolt patterns and sealing surfaces.

What should I expect during installation and maintenance?

Installation requires typical engine access to the rear crank area and basic mechanical skills; removal of drivetrain components or engine support may be necessary on some vehicles. Clean mating surfaces thoroughly and follow torque specs for bolts to prevent leaks. Routine inspection after installation is recommended to verify the seal is performing as intended and to catch any adjacent oil leaks early.

• Prepare by cleaning the block sealing surface and checking for damage.
• Use correct torque values and sequence when tightening bolts.
• May require transmission/driveshaft removal on certain models.
• Inspect after initial road use to confirm no seepage at the joint.

Why choose this AUTOBABA kit over a single-part replacement?

The kit approach supplies the cover, gasket and bolts together so you replace all sealing elements at once, reducing the chance of rework from missing or corroded hardware. Buying a full kit simplifies procurement and helps ensure a consistent fit and finish comparable to the engine’s original sealing surfaces. It’s particularly useful when replacing an older, damaged or corroded rear cover.

• Complete kit minimizes parts mismatch and follow-up repairs.
• Hardware included to replace brittle or corroded bolts.
• Aluminum cover reduces long-term corrosion risk compared to some alternatives.
• Manufactured to align with common OEM mounting patterns.

Who is this for: This AUTOBABA rear main seal cover kit is intended for professional mechanics, experienced DIYers and fleet technicians working on GM-platform vehicles that use the listed engine sizes and part numbers. If you need a direct replacement for part 635-518 / 12633579 / 12639250, want a corrosion-resistant aluminum cover, and prefer a complete gasket-and-bolt kit to streamline installation, this product is a suitable choice. Always verify compatibility with your vehicle’s year, model, and engine before ordering.