2007 Chevy Silverado 2500HD - Solid Axle Addiction
It's funny how one component can make or break the image of a truck. When General Motors announced in 1991 that its 1-ton pickups were switching to independent front suspension (IFS), there was a cry heard around the world. That cry was for the loss of the Dana 60 front axle that had been fitted to every four-wheel-drive 1-ton GM pickup since 1977. That cry still echoes to this day.
Ford and Dodge truck engineers must have rejoiced over the news. For in the heavy-duty truck market, there's no substitute for the simplicity, strength, and reliability of a solid axle. Maurice Rozo of Burbank, California, couldn't agree more. As a Chevy guy, he cringed at the loss of the Dana 60 axle in the GM lineup. Unlike the rest of us who could do nothing but complain about it, Maurice came up with a solution. He built his own GM solid axle suspension kit.
BORN IN BURBANK
Working with a team of fabricators and designers at his shop, Off Road Unlimited (ORU), Maurice spec'd out a kit that would allow '92-and-newer GM 3/4- and 1-ton truck owners to install a Ford-style Dana 60 front axle in their truck utilizing commonly available leaf springs. Off Road Unlimited made a name for itself offering this kit to the public, as well as developing other proven off-road suspension, steering, and drivetrain products.
Over the years, most of the solid front axle GM trucks that you've seen on the road are either running ORU parts, or appear to have taken cues from the ORU kit. We've even seen Jim Carrey, the famous actor, driving a 3/4-ton solid axle GM truck that Off Road Unlimited built.
Recently, Off Road Unlimited has revised its solid axle swap kit to not only work with General Motors' latest GMT900 3/4- 1-ton chassis, it's now developed a package that includes a four-link suspension and coilover shocks for '01-and-newer trucks.
It's hard to believe, but Maurice's "Red Addiction" Chevy began life as a two-wheel-drive truck. After years of doing more solid axle swaps than anyone else, the one thing Maurice has never been completely satisfied with is the New Venture Gear transfer cases that the '01-and-newer Duramax trucks come with. Since Maurice knew he was going to ditch all of the factory four-wheel-drive components, he figured he should just start with a two-wheel-drive truck instead.
Maurice ordered an '07 Silverado 2500HD with the LMM Duramax and Allison 1000 transmission. His solid axle upgrade kit is designed to work with both two- and four-wheel-drive GM truck frames, so that only left fitting the truck with a transfer case. For that, Maurice made a call to Advance Adapters, in Paso Robles, California, and ordered an Atlas II transfer case with a 3:1 low-range.
Now, the Duramax's torque is transferred through the stock two-wheel-drive Allison 1000 six-speed transmission and sent back to a divorce-mounted Atlas transfer case. From there, the power is sent through a pair of driveshafts to the AAM 1150 rear and a custom-built Dynatrac Pro 60 front axle bolted in with ORU's latest four-link front suspension kit.
HOW STRONG IS IT?
The gross axle weight rating (GAWR) of the GM 3/4-ton independent front suspension is 4,600 pounds. That means the front end is rated to support a little over 2 tons, which gives an indication of the strength and durability of GM's IFS. A Dana 60 axle, on the other hand (one built to the specs of the Dynatrac Pro 60 in Maurice's truck), has a GAWR of more like 5,500 pounds, giving it 900 pounds more capacity to take a pounding without breaking so much as a sweat.
We can attest to the strength of Maurice's 2500HD as we drove it 200 miles to our cover photo shoot, watched Maurice beat on it, and then drove it 200 miles back home. Nothing we could do to the truck phased it in the least, and the truck came home needing only a new rear bumpstop, a fresh tank of fuel, and a good truck wash. Now that's what we call heavy duty!
Photo Gallery: 2007 Chevy Silverado 2500HD - LMM Duramax Diesel - Diesel Power Magazine
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