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  • Steering Simplified - Up Close With The Parts That Turn Your GM

Steering Simplified - Up Close With The Parts That Turn Your GM

What To Upgrade On Your GM Truck

The ManufacturersAug 27, 2013
In 1988, GM replaced the tried-and-true Dana 60 front axle that resided under the front of the company’s heavy-duty trucks with a more modern, independent front suspension (IFS). With the new suspension came a new style of steering, never before seen on a four-wheel-drive heavy-duty pickup truck. Fast-forward 25 years, and while improvements have been made, we still find this same basic steering system alive and well under GM’s HD lineup.
Photo 2/12
While slightly more complex than the systems used to guide the current Ram and Ford trucks, GM’s steering is nothing to be feared. And, with a little thoughtful planning, this steering can be built to handle boosted launches at the dragstrip, full pulls in the dirt, and all the horsepower your Duramax can throw at it. In the following pages, we’ll take you through the six basic components that make up the system, explain how and why they work (and where they fail), and show you ways to improve their performance.
Steering Shaft
A commonly overlooked yet very important piece of hardware is the steering shaft. This shaft links the steering wheel in the cab to the steering box mounted on the frame and provides the physical connection between a driver’s input and the road. Sometimes a clunking or ratcheting feel in the steering is experienced by ’01 to ’09 Duramax owners. As a fix for this, Borgeson offers an upgraded direct-replacement steering shaft that is a permanent solution— and a must for trucks running larger-than-factory tires.
Photo 3/12   |   Borgeson is pretty much the only game in town when it comes to steering shafts. A new shaft can be installed with basic handtools in about an hour.
Steering Box
Connected to the end of the steering shaft is the gearbox. Using a combination of gear reduction and hydraulic pressure, the steering gearbox is responsible for directing a driver’s input to the wheels. Although this is one of the heartiest parts of the system, over time the internal gears can begin to wear, resulting in slop in the steering wheel, or they can develop a leak that gets worse as time goes on. The gear mesh inside the box can be adjusted, but once this is exhausted, it’s time to find a replacement. Upgraded boxes can be had from Borgeson, Red Head, Lee, and many others.
Photo 4/12   |   The steering box is located along the inside of the driver-side framerail, in front of the engine. Replacement is a full day’s work and will require the power steering pump to be bled.
Pitman and Idler Arm
One of the more confusing parts of the GM HD steering system is the pitman and idler arm arrangement. Put simply, the pitman arm connects the steering gearbox to the centerlink, while the idler arm supports the opposite end. Both arms are cast steel units with integrated ball joints. These joints are designed to move only along a horizontal plane and, with proper maintenance and grease, can last for a very long time. Upgraded arms are available from PPE and are precision machined and equipped with a massive 7⁄8-inch bolt. The most popular pitman and idler arm modification for trucks that are lifted, drag race, or sled pull is a support kit. While there are many companies producing these kits, they all function in the same basic fashion. All use frame-mounted brackets and Heim joints to place the idler and pitman arm joints in double sheer, where they connect to the centerlink. This prevents the centerlink from rocking back and forth while allowing the side-to-side movement necessary to steer.
Centerlink
Connecting the pitman and idler arms together is a centerlink. This solid bar is also the inner mounting point for the tie rods. The centerlink is often overlooked when upgrading the steering system, and for good reason: it’s the simplest. With no moving parts, good thickness throughout, and support at both ends (pitman and idler arms), there is really no need to ever replace this piece. For those who want the best of the best, PPE offers a machined, straight, 304 stainless steel unit. However, these are recommended for race or off-road use only due to the potential for increased bumpsteer.
Photo 7/12   |   For drag race and sled pulling applications, the ultimate in strength can be found in a straight centerlink. Removing the bends reduces the truck’s natural want to toe-in under load. Installation can be completed in a few hours but will require an alignment since the tie rods must also be removed.
Tie Rods
The weakest link in the entire system is the tie rods. Tasked with multiple duties, the tie rods are responsible for connecting the steering knuckle to the centerlink, must be able to pivot both vertically and horizontally as steering and suspension angles dictate, and are adjustable for setting proper toe alignment. Like most of the suspension parts, a stock truck’s factory tie rods do their job. However, as soon as anything is changed—such as adding a front locking differential, larger tires or wheels, or a suspension kit—they quickly become inadequate. Add in the stresses created during boosted four-wheel-drive launches or sled pulling, and catastrophic failure is not far off. Fortunately, there is an easy and inexpensive fix for this universal issue, which is to sleeve them. Many companies manufacture steel, stainless steel, and even aluminum tie-rod sleeve kits. For even more strength, companies such as Fabtech and Camburg Engineering offer complete heavy-duty replacement tie rods. If you want the most extreme parts available, turn to Cognito Motorsports or Readylift for tie rods built with either DOM or chromoly tubing and Heim joints for pivots.
Ball Joints
Ball joints on an IFS truck are possibly one of the most underrated components. Unlike a solid axle, in which the ball joint’s job is to support and facilitate horizontal steering movement, the ball joints on an IFS truck also have the task of controlling vertical suspension movement. Located in the upper and lower control arms, these small joints will last an incredibly long time with routine maintenance and greasing. However, cranking up the torsion bars, installing lift kits, and adding larger, heavier tires will wear them out at an accelerated rate. Fixing worn-out ball joints can be done easily by replacing the upper and lower factory units with new, pressed-in MOOG joints from a local parts house, or installing a complete stock replacement upper control arm and pressing in a new lower. Many companies also sell upgraded upper control arms with heavy-duty ball joints or race-inspired uniballs for maximum strength.
Photo 11/12   |   The ball joint on this ’11 GMC is cast into the upper control arm and should be replaced as a complete unit and in pairs. This task can be completed in a day, with an alignment required. It’s also worth noting that not all years are the same, and some upper ball joints can simply be pressed out and replaced.
Solid Axle Swap
With tires that are way too large, power that is too much to handle, or when all other options have simply been exhausted, GM owners can turn to a solid axle swap. Companies such as Offroad Design and Off-Road Unlimited both offer bolt-on kits that convert the factory IFS to either leaf springs or a multi-link suspension system. The advantage to the solid axle swap is the increased strength attained from the ability to run a Dana 60 or larger front axle and from the improved design of a drag link–type steering setup. Unfortunately, the disadvantages are also great, as this type of setup comes with a high price tag, added complexity and, oftentimes, quirky road manners.
Photo 12/12   |   While not necessarily the best choice for racing, if off-road is your thing and you’re having a tough time keeping frontend components alive, a solid axle swap might be a good route to take. But be warned: These swaps come with an entirely different list of challenges.

Sources

ReadyLift
Santa Ana, CA 92704
800-549-4620
www.readylift.com
Camburg Engineering
Huntington Beach, CA 92647
714-848-8880
http://www.camburg.com
Offroad Design
970-945-7777
www.offroaddesign.com
Offroad Unlimited
Burbank, CA 91504
818-848-2020
http://www.offroadunlimited.com
Pacific Performance Engineering
Fullerton, CA 92831
714-985-4825
www.pacificp.com
Cognito Motorsports
Bakersfield, CA 93312
866-426-4648
http://www.cognitomotorsports.com
Alligator Performance
866-255-7212
http://www.alligatorperformance.com
Diesel Power Products
866-379-8685
www.dieselpowerproducts.com
Off-Road Unlimited
877-563-1208
http://www.offroadunlimited.com
Borgeson
Torrington, CT 06790
860-482-8283
www.borgeson.com

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