Duramax Suspension Upgrades

These products are popular suspension and steering options for your Duramax. However, to see all of the available options, please select your vehicle application from the top menu and navigate to the appropriate category.

One thing is for certain when it comes to the Duramax powered heavy duty line of Chevrolet and GMC’s, they are consistent. Compared to their competitors, GM has maintained the same basic powertrain, suspension, and even overall aesthetics since the inception of the Duramax powerplant back in 2001 model years. And why not? With exception to certain issues that plagued various model year ranges, for the most part, these series of trucks are truly a very dependable, hard working pickup. Nonetheless, one area that they have stuck to their guns and been ridiculed for doing so by Ram and Blue Oval advocates, is the continued use of their independent front suspension, or IFS for short. While a straight axle, as used on Ram and Ford models, is inevitably stronger than IFS, does that mean that an independent front suspension is an overall inferior design, or possibly the slight loss in integrity is outweighed by the functionality? Before we can dive into this debate, we should first start off with how it all works and any changes that have taken place over the years.

In comparison to a standard straight front axle, which features a differential in the middle of the axle housing, an IFS’ differential is attached to the frame. Protruding from opposing ends of the differential are half shafts with constant velocity (CV) joints that run to the knuckles at the wheels. This allows for each front tire, wheel, and knuckle assembly to move independently of the opposing side. This is in sharp contrast to a straight axle design that will always put some type of opposing force on the wheel opposite to which the initial action is occurring. Next, the steering knuckles are supported by upper and lower A-arms that run perpendicular to the frame rails. Unlike other manufacturers that use similar A-arm designs, GM has always placed its upper A-arms on the outside of the frame rail, which allows for a wider track width, delivering more stability.

Since the IFS design does not utilize a front coil or leaf spring, it instead uses torsion bars. These are essentially tubes that run parallel to the frame rail and connect on one end to a cross member located roughly at the transmission, and the other end is affixed into the front lower control arms. At the cross member connection point, the bar is installed into what is known as a torsion bar key, which is responsible for adjusting the front ride height depending on how much rotational force is applied to the keys and torsion bars.

Beginning with the redesigned 2011 model years, the front end was strengthened in comparison to the 2001-2010 models in an effort to properly support the higher power and tow rating of these vehicles. The most noticeable change was to that of the control arms. These trucks were treated to forged steel upper arms and cast iron lowers coupled with larger diameter torsion bars. Also to support the higher tow capacity, GM upped the ante out back with revised leaf spring packs. The 2500 models would be treated to a two stage where the 3500’s got a three stage design in an effort to reduce axle hop while towing at or near the increased GAWR (Gross Axle Weight Rating).

Now that you have a basic understanding of this suspension, what are the little nuances and intricacies of it? Simply put, everything in the Chevy’s IFS is at its strongest when its working in a straight line. The less angle on the CV (Constant Velocity) shafts, steering linkage, and ball joints, the stronger the front end is. However, when adding a suspension system or lift kit to the truck, these angles can and will all change. Because of this, its imperative to choose a suspension company that addresses all of these angles and accounts for them with components that realign the parts to avoid the complete degradation of the ride quality. Ideally, after lifting, the CV shafts and tie rods should remain parallel as power is being applied. Doing so will allow your truck to be more capable off road, be able to survive the rigors of sled pulling, and successfully launch in four wheel drive without breaking CV’s or tie rods. Overall, the biggest weak points in this system are the tie rods, pitman arm, and idler arms. And fortunately, the aftermarket has support for all of these with upgrades that can handle the stress of big power and abuse, eliminating the need, as some may think, to go through the arduous effort of performing a straight axle conversion.

As always, if you have any questions on how your IFS works or can it can be upgraded to suit how you specifically use your truck, don’t hesitate to give us a call or shoot an e-mail to [email protected] and we would be happy to assist.

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