Level Up! BDS Suspension’s Coilover Conversion for GM HD Trucks [Video]
As the only one of the big three to offer an independent front suspension on its ¾- and 1-ton trucks, GM has built a reputation around HD truck refinement. While the IFS versus solid axle debate still remains an active topic among truck enthusiasts, there’s no question that IFS has dominated the ½-ton truck market. This IFS takeover is one of the reasons late-model pickups ride and drive so well.
At the top of GM’s pickup pyramid is the GMC HD Denali. Optioned with the available Duramax diesel engine, the 2018 ¾-ton version you’ll find featured here is an outstanding example of the modern luxury and capabilities fit into these cutting-edge platforms. Despite being flooded with power and technology, one area remains largely outdated: the torsion bar front suspension. While it did see a refresh in 2011, the basic torsion bar design has remained under GM trucks for nearly 30 years.
The shortcomings of a torsion bar setup are generally not revealed until owners attempt to raise the front of the truck to create a more level stance. The limited available suspension travel combined with the added pre-load necessary to increase the front end equates to reduced ride quality and suspension performance. Yes, the nose-down stance of the truck is by design and helps prevent the front end from pointing skywards when towing. However, for the owner of this 2018 HD Denali, he didn’t care for the look of the stock nose-down rake. As for the nose pointing skyward when a load is added, that’s easily prevented by installing a set of helper air bags out back.
Having not been satisfied with the ride quality and performance of previously installed torsion bar leveling keys, he opted to spend a little more money for a substantial suspension upgrade from BDS Suspension. The company’s 2-3-inch Coilover Conversion removes the original torsion bar setup entirely, along with the original upper and lower control arms. While it’s a drastic change over the stock setup, there’s very little welding and drilling required. We’re highlighting some of the most important aspects of the conversion in the article breakdown below, but for the full review, be sure to check out the video up top.
Having the ability to fine-tune your truck’s suspension is part of the value brought with this kit. Attached to the remote reservoirs on the Fox 2.5 coilovers are dual speed compression adjusters. This allows you to adjust the compression (upwards movement of the shock) settings for low and high speed performance. With a quick twist of the knobs, you can easily compensate not only for the terrain you’re on, but adjust the settings to fit your specific driving style and truck setup.
To create 30 percent more suspension travel, BDS includes new upper and lower control arms. While the upper is a tubular style, the bottom is a massive plate-steel unit that’s internally reinforced. Each arm is fit with factory style rubber bushings at the frame side and premium Moog ball joints at the steering knuckle.
The coilover tower takes advantage of existing holes in the GMC’s chassis and requires minimal drilling, making for an easy bolt-on install. While the shocks come pre-set at 2.5 inches of lift, BDS sends an adjustment tool for you to dial in the ride height to your liking. Another nice touch is the billet cap that protects the upper ball joint.
Out back, you can opt for a lift block, add-a-leaf or simply install the provided Fox 2.0 shocks. Given this owner was only looking to level the truck, he opted to leave the rear suspension stock and just add in the new suspension dampener.
Better Wheels and Tires
Since BDS retains the stock steering knuckles, the only track width change came from the new 20x9 Hostile H115 Predator series wheels.
With the front of the truck raised, there was room for a larger set of treads. These 35x12.50R20 Nitto Terra Grappler G2 tires come with a load range F sidewall, making them ideal for HD applications such as this. The fact that these ultra-quiet all-terrains are fit with heavy siping and deep lugs means the tires can find grip easily on-road and off.
Driving Is Believing
This truck is currently being used to help with the recovery efforts from Hurricane Florence in Wilmington, North Carolina. As such, it’s currently fit with a 100-gallon diesel transfer tank in the bed. Even with the added weight out back, the truck is nearly perfectly level. Once the clean-up effort is complete, the next modification will be for a set of helper air bags out back. These will ensure the truck always stays level, no matter the load.
Getting behind the wheel with this kit will sell you on how great it is. This particular truck now rides and handles more along the lines of a ½-ton truck, which is pretty amazing. On-road, the suspension does an excellent job at soaking up imperfections in the road and improving the overall handling. Off-road, the frontend no longer bounces over bumps, but rather absorbs the uneven terrain with ease. Overall, it’s lightyears better than the torsion bar design and something we’re surprised GM isn’t offering from the factory.