6.6L Duramax

Doc's Diesel 6.6L Duramax Parts

From LB7 to L5P, Every Generation Covered.

Since 2001, the 6.6L Duramax has been GM's answer in the heavy-duty diesel wars—and a quarter century later, every generation from the original LB7 to the current L5P is still out there towing, hauling, and stacking miles. Each era has its own filters, its own quirks, and its own owners who plan to keep it forever. This collection is Doc's complete 6.6L coverage: whatever year Silverado HD or Sierra HD you run, the maintenance parts that fit are here.

Twenty-Five Years, Sorted by Generation.

Oil filters, fuel filters and fuel/water separators, engine air and cabin air filters, complete filter kits and maintenance kits, heavy-duty diesel oil at the correct 10-quart capacity, and treatments for fuel, oil, and winter—organized across every 6.6L generation from 2001 to today, because an LB7 and an L5P share a displacement and almost nothing else.

Built to OEM Specs. Backed by the Doc's Fitment Guarantee.

Every part meets or exceeds OEM design, fit, and function, keeps factory warranties intact when installed correctly, and carries the Fitment Guarantee: doesn't fit your Duramax, we make it right. No guesswork. No BS.

Doc's Makes It Easy.

With five generations under one badge, start at the Vehicle Selection Tool—enter your exact year and we'll show only what fits. And keep fuel filtration tight on the common-rail trucks; clean fuel is the cheapest thing you'll ever do for a set of injectors.

Free Shipping on All U.S. Orders $99+

Stock the season in one order and everything over $99 ships free anywhere in the U.S. Twenty-five years of Duramax, covered end to end—that's the Doc's way.