GM GENUINE PARTS Crankshaft Rear Main Seal 89060436 — OE-fit, oil- and heat-resistant replacement

GM Genuine Parts 89060436 Crankshaft Rear Main Seal provides an exact OE-fit replacement that helps maintain a secure oil seal at the rear of the crankshaft.

The 89060436 rear main seal is an original-equipment style component engineered and validated by General Motors to match factory specifications. Made to resist heat, pressure, and engine oil exposure, this seal replaces the worn or damaged rear crankshaft seal to reduce oil leaks and restore the crankshaft-to-block barrier. As a GM Genuine Parts item, it follows the same design, materials, and testing protocols used in vehicle production—offering consistent fit, form, and function compared with aftermarket alternatives.

How does this rear main seal prevent oil leaks?

The seal creates a tight interface between the rotating crankshaft and the engine block to block oil migration out of the crankcase. Its elastomeric lip and metal-reinforced carrier are shaped to maintain contact under thermal expansion and shaft movement. Using the factory-spec materials helps it resist degradation from engine oil and heat.

• Elastomer sealing lip designed for continuous contact with crankshaft
• Metal carrier for consistent mounting and concentricity
• Formulated for oil, heat, and pressure resistance
• Manufactured to GM OE dimensional tolerances

When should I replace the rear main seal on my GM vehicle?

Replace the rear main seal if you see persistent oil dripping under the vehicle, oil on the transmission bell housing, or after removing the transmission for clutch or flywheel work. Seals also harden and lose elasticity over time; preventive replacement during major engine service avoids future leaks and labor duplication.

• Visible oil spots under the rear of the engine
• Oil contamination on clutch or transmission components
• Engine overhaul or transmission removal service
• High-mileage vehicles with age-related seal hardening

Will this GM Genuine Parts seal fit my vehicle and perform like the original?

Yes — the 89060436 is built to GM original-equipment specifications for proper fit and function where it’s listed as the correct part number. Using a GM Genuine Part preserves factory clearances and mounting interfaces, reducing the need for seal modifications or adapters. Always verify part compatibility with your VIN or parts catalog before ordering.

• Manufactured to original GM design and tolerances
• Direct replacement for specified GM applications
• Quality control and testing consistent with factory parts
• Backed by GM parts validation and support

How do I ensure a proper installation for long service life?

Correct installation is essential: clean the crankshaft surface, inspect the shaft for wear, and use the proper alignment tool to seat the seal squarely. Lightly lubricate the sealing lip with clean engine oil and torque any retaining hardware to factory specs to avoid distortion. If unsure, have a professional technician perform the replacement to prevent premature failure.

• Clean and inspect shaft and housing before fitting
• Use OEM installation tool or appropriate driver to press in evenly
• Lubricate lip with clean engine oil to prevent dry starts
• Confirm torque values and clearances per service manual

Who is this for: The GM Genuine Parts 89060436 Crankshaft Rear Main Seal is intended for owners, mechanics, and fleets needing a direct factory-spec replacement for a leaking or worn rear crankshaft seal on compatible GM vehicles. It’s ideal for those who want OE-level reliability during engine repairs, clutch or transmission service, and routine preventative maintenance. Choose this part when preserving factory fit and long-term performance matters more than short-term cost savings.