Engine Rear Main Seal Cover Kit with Gasket & Bolt - Durable Fit

In this review the Engine Rear Main Seal Cover Kit is evaluated for owners who need a reliable rear main seal solution for a wide range of GM vehicles. The reviewer found this kit useful for mechanics and DIYers because it matches OEM dimensions, is constructed from aluminum for corrosion resistance, and includes gasket and bolts to simplify installation. The single biggest reason to buy is the combination of broad OEM-compatible fitment and a solid metal cover that reduces the chance of leaks over time.

Key Features

• Broad fitment: Covers many Chevrolet, GMC, Cadillac and related models so a single part number fits dozens of older and newer vehicles.
• OEM compatibility: Designed to replace part numbers 635-518, 12633579 and 12639250, providing confidence that it matches factory dimensions.
• Aluminum construction: The high quality aluminum body offers corrosion resistance and long term durability compared with softer materials.
• Complete kit: Includes gasket and bolts so the installer does not need to source additional hardware for a standard replacement job.
• Service friendly: The cover simplifies rear main access during engine service and helps ensure a clean, leak-free seal when installed correctly.

Who It's For

This kit is aimed at professional mechanics and experienced DIYers working on GM V8 and V6 engines across trucks, vans and performance cars from the late 1990s through mid 2010s. It is particularly useful for anyone restoring engines, repairing a rear main leak, or replacing a failing original cover where OEM fit is required.

Those who should look elsewhere include owners of vehicles outside the long list of compatible models or buyers who prefer a replacement from an OE dealer with direct factory warranty paperwork; always check fitment before purchase to confirm compatibility with the specific year and engine.

Pros & Cons

Pros

• Durable aluminum construction reduces corrosion risk and extends service life.
• Comprehensive fitment across many Chevy, GMC, Cadillac and other GM-related models.
• Kit includes gasket and bolts for one-stop replacement and easier installation.

Cons

• Fitment requires careful vehicle verification because the same engine families span many model years and variants.

Specifications

Our Verdict

The Engine Rear Main Seal Cover Kit is a practical, cost-effective replacement for anyone who needs an OEM-compatible cover that resists corrosion and comes as a complete kit. For mechanics and knowledgeable DIYers working on compatible Chevy, GMC or Cadillac engines, it delivers solid value by reducing additional parts sourcing and offering long lasting aluminum construction.

Frequently Asked Questions

Will this cover fit my vehicle?
Check the detailed fitment list and compare part numbers 635-518, 12633579 or 12639250 with your vehicle to confirm compatibility before purchase.

What is included in the kit?
The kit ships with the aluminum rear main seal cover, a matching gasket and the required bolts for installation.

Is the cover corrosion resistant?
Yes, the cover is made of high quality aluminum designed for corrosion resistance and long durability.