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2001-2004 Duramax 6.6 LB7

The GM Duramax engine was first introduced to the US diesel pickup and chassis cab markets in 2001. The LB7 Duramax was a major turning point for GM, as it offered superior performance compared to any diesel engine GM had offered up to that point. The Duramax LB7 was available in the 2001-2004 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD, as well as the medium-duty Chevrolet Kodiak and GMC TopKick.

The LB7 Duramax was a remarkable engine that provided outstanding power and efficiency. It was designed with a heavy-duty Allison 1000 five-speed automatic transmission, which managed the engine's power with ease. The ZF six-speed manual transmission was also offered, but the Allison 1000 was the more popular option by a wide margin.

The Allison 1000 was a groundbreaking transmission for its time, as it was the first automatic transmission in its class to be worthy of being mated to a diesel engine. The Allison 5-speed automatic transmission was known for its reliability and durability, and it quickly became the preferred option for buyers.

Despite its impressive performance, the LB7 Duramax was not without its issues. The engine was plagued with fuel injector problems, which were so frequent that GM had to recall the original units and replace them with an updated design. The factory warranty was also extended to cover the new injectors for a period of 7 years or 200,000 miles.

Despite these issues, the LB7 Duramax proved to be a revolutionary engine platform for GM, and it set the standard for the diesel pickup and chassis cab market. The engine's power and efficiency, combined with the Allison 1000 transmission, made it a winning combination that could not be matched by any other diesel engine in its class.