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6.6L Duramax Diesel Chevy - HD Squared

Posted in Features on March 11, 2008
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If there's an OEM trend we like, it's the trend toward better-equipped, warranty-backed trucks that can drive off the dealer's lot straight into the work world or onto the trail. Chevy's Heavy Duty series joins ranks with other factory-built powerhouses such as the Jeep Wrangler Rubicon, the Dodge Power Wagon, and the Ford Super Duty.

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Right out of the box, the HD bristles with a pretty impressive drivetrain. Power generation begins with a 6.6L Duramax Diesel and feeds into an Allison automatic transmission. After being split at the transfer case, power is then routed to big-time beef in the form of an AAM 11-1/2-inch full-floating rearend factory equipped with disc brakes. The front differential is on par with the rear: the 9-1/4-inch ring gear is reverse-cut/high-pinion, which makes it ideal for front applications and provides about 4 inches of additional ground clearance compared to a standard-cut/low-pinion frontend.

If there's a weak spot in the HD's off-road armada, it's the lack of clearance for the oversize rubber that off-roaders want to install. Big tires offer big floatation for navigating soft sand and big grip for clawing at rocks and hardpack. Enter Fabtech Motorsports.

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When designing its HD suspension system, Fabtech took into consideration that many truck owners want to leave their body panels unmodified, and that those same owners want a simple installation experience. As such, the Fabtech 8-inch HD suspension is catalogued to complement tires as large as 37 inches without modified body panels. Installation is possible in a driveway in conjunction with an average selection of tools and intermediate mechanical aptitude. Of course, fender trimming will allow even bigger meats to roam beneath the HD.

As an option, HD owners can also choose to equip their lifted rides with Fabtech's new line of Dirt Logic shocks. Featuring high-quality USA construction and generous oil capacity, the Dirt Logic dampers can be rebuilt and revalved for long life and fine-tuning.

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Does it work? Fabtech's Jason Jones began by telling us that this very truck towed an 11,000-pound Payload up I-15 to the annual SEMA show and back. For those unfamiliar with this particular stretch of asphalt, it is laden with several brutal grades that unearth any weakness in power output or cooling system efficiency. The route's nastiest hill is known as Baker Grade, where it's not uncommon to see Grade victims pulled to the side of the road, hoods raised in defeat. Towing and mechanical help command a king's ransom in the Baker area; it's not a wallet-friendly place for trouble. The Fabtech HD took itself, the laden trailer, and its amazed driver over the grade without slowing and without the exhaust gas temp-erature gauge getting anywhere near the dreaded red zone. Jason answered the rest of the "does it work?" question by flogging the HD in the dirt for our eyes and lenses. Yes, it works.

Chevy got the HD pointed in the right direction with a stout drivetrain that loves to tow. Fabtech got the HD into the dirt with clean design, heavy-duty construction, and race-bred dampers. HD squared.

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