Choosing the Right Valve Stem Seal for 2006-2010 GM Trucks & Vans with Duramax 6.6L Engine

Design Matters

In use since 2001, General Motors’ Duramax 6.6L diesel engine powers popular vehicles like the Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks, as well as Chevrolet Express and GMC Savana 2500/3500 vans. Renowned for its towing and hauling capabilities, this workhorse delivers impressive power and efficiency. When servicing valve stem seals, it's crucial to pay close attention to the valve guide design to ensure the correct replacement parts are used.

Inside the Issue

The Duramax 6.6L engine featured an early-design valve guide from 2006 to 2010, while a late-design valve guide was introduced in 2011 and later model years. However, an early- design engine may contain late-design valve guides if the cylinder head or valve guides have been replaced, requiring the use of late-design valve stem seals. This variability makes it difficult to identify the correct part simply by looking up the application in the Fel-Pro part finder.

Later-design valve guides use pressed-fit valve stem seals, which require an updated seal design. While the early design valve guides were hand installable, proper installation of the late-design seals demands a specialized installation tool (GM # EN-49761) to ensure correct depth placement. If installed incorrectly, the seal can be damaged, potentially leading to excessive oil consumption.

Identifying Valve Guides

The key distinguishing feature of the valve guides is the valve stem seal locating groove. The early-design hand-installable version, which incorporates this groove, uses Fel-Pro part SS 72916 (GM #97212994).

The late-design valve guide, which lacks a locating groove, utilizes a pressed-fit valve stem seal Fel-Pro part SS 72551 (GM #12624396). To ensure proper installation, GM tool EN-49761, or an equivalent tool, must be used to set the seal at the correct depth.

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The content in this article is for informational purposes only. You should consult with a certified technician or mechanic if you have questions relating to any of the topics covered herein. DRiV and its affiliates (including Federal-Mogul Motorparts LLC) will not be liable for any loss or damage caused by your reliance on any content.