Genuine GM LS Rear Engine Cover with Rear Main Seal, Gasket & Bolts - 12639250

Genuine GM rear engine cover (rear main seal housing) for Gen III/IV LS engines — GM part number 12639250. Comes as a complete service assembly with the rear main seal pre-installed, rear cover gasket fitted, and mounting bolts included, so it's a clean one-step fit.

This is the updated GM casting that supersedes the earlier covers known for porosity and cracking — a common cause of oil leaks often misdiagnosed as rear main seal failure. If you're doing a rear main seal on an LS, replacing the cover at the same time is the proper fix.

• GM part number: 12639250 (supersedes 12556105, 12559287, 12572013, 12572014, 12587100, 12598301, 12606502, 12614813, 12615666, 12633579)
• Fits Gen III/IV LS V8s: 4.8L, 5.3L, 5.7L, 6.0L, 6.2L (LS1, LS2, LS3 and truck variants)
• Suits Holden VT–VF Commodore V8 applications (LS1, L76, L77, L98, LS2, LS3)
• Includes: cover, rear main seal, gasket, and bolts
• Brand new in GM Genuine Parts box