Product Description
The GM 12637785 Grade C Left Side Cylinder Head Gasket is the OEM sealing solution for the driver side cylinder head on 2001–2016 GM 6.6L Duramax diesel engines. Manufactured to GM factory specifications, this gasket features a Grade C thickness of 1.05mm to maintain proper compression ratio, cylinder sealing, and long-term reliability.
Whether you are performing a complete engine rebuild, repairing a failed head gasket, or installing upgraded head studs on your Duramax, the GM Genuine 12637785 gasket ensures proper sealing between the block and cylinder head under extreme diesel combustion pressures.
Fitment
- 2001–2004 GM Silverado / Sierra 2500HD & 3500 — 6.6L Duramax LB7
- 2004.5–2005 GM Silverado / Sierra 2500HD & 3500 — 6.6L Duramax LLY
- 2006–2007 GM Silverado / Sierra 2500HD & 3500 — 6.6L Duramax LBZ
- 2007.5–2010 GM Silverado / Sierra 2500HD & 3500 — 6.6L Duramax LMM
- 2011–2016 GM Silverado / Sierra 2500HD & 3500 — 6.6L Duramax LML
- Engine: GM 6.6L Duramax Diesel
- Side: Left / Driver Side
- Thickness: 1.05mm
- Grade: C
- OEM GM Genuine Part
Specifications for GM 12637785
| Specifications for GM 12637785 | |
|---|---|
| UPC | 0808709358824 |
| GTIN | 0808709358824 |
| Shipping Info | Shipping Weight: 1 lb Package Dimensions: 23 x 9 x 1 inches |
| Prop 65 | WARNING: Cancer & Reproductive Harm – www.P65Warnings.ca.gov |
FAQ
Is GM 12637785 the driver side head gasket?Yes. GM 12637785 is the left side (driver side) cylinder head gasket for the Duramax engine platform.
What thickness is this Duramax head gasket?
This gasket is a Grade C thickness measuring 1.05mm, which is commonly used in many factory Duramax engine configurations.
Which Duramax engines does this gasket fit?
It fits all 2001–2016 GM 6.6L Duramax engines including LB7, LLY, LBZ, LMM, and LML.
Should head bolts or studs be replaced when installing a new gasket?
Yes. GM recommends replacing torque-to-yield head bolts or upgrading to performance head studs whenever cylinder heads are removed.
