2005 GMC Duramax Jounce Shocks - Photos

Once the alignment arm was in place, our installer, Travis, moved on to the upper Jounce Shock mounts. This step required the removal of paint from an area of the frame between the shock bucket and the upper A-arm pivot point. This would provide a clean surface to which the upper Jounce Shock mount could be welded. It is recommended that a skilled welder complete this step as spatial constraints limit welder access, and a great deal of force relies on the integrity of these welds. Here is the bracket just before it was welded to the frame. It comes with a special weldable primer coating to prevent rust prior to installation. This bracket is easy to line up because it has an exact fit to the concave contour of the frame.

Shortly after our test session, we took a ride in one of Light Racing's Jounce Shock-equipped 1/2-ton Chevy pickups. Needless to say, our jaws dropped when the company's vice president, Bryan Kudella, skied the vehicle without drama. We were amazed with the vehicle's ability to soften a landing that would normally destroy the bumpstops of any stock suspension. The best part was when he asked if we wanted to do it again. Bryan continued jumping the truck for us until we'd had enough. After more than a dozen jumps, there was no evi dence of damage to any part of the OEM suspension. The Jounce Shocks did their job.

Another product Light Racing developed for the Military that we thought worth mentioning is its new RokArmor skidplate system. It fits all '01-and-newer GM 1/2- and 3/4-ton pickups. The system uses high-strength 6061-T6 aircraft-grade aluminum to protect the vehicle's vital components. It does require some drilling, but it protects everything from behind the bumper to the transfer case. The RokArmor system has a steel subskeleton support structure that allows jacking from any given point of the skidplate. The kit takes a few hours to install, but is second to none in quality and ground clearance.

The Jounce Shock has been installed into the upper and lower mounts. Note that the alignment arm is free-floating from the lower A-arm. This ensures the Jounce Shock will not limit downward force of the lower A-arm. In other words, the Jounce Shocks only work during suspension compression.
The Jounce Shock has been installed into the upper and lower mounts. Note that the alignme
This is what happened to one of the OEM front bumpstops when we conducted a testdrive before installing the Jounce Shocks. Notice how the rubberized material was damaged by excessive force during a hard bottoming-out. The vehicle speed at which this damage occurred was 15 mph. We were surprised to learn just how susceptible to damage these bumpstops were. The Jounce Shock system doesn't replace the OEM bumpstops. In fact, the installation instructions recommend cutting them in half with a Sawzall and reinstalling them as backups in case one of the Jounce Shock cylinders should ever fail.
This is what happened to one of the OEM front bumpstops when we conducted a testdrive befo
It was much simpler to install the Jounce Shocks on the rear of our donor truck. First, a template was used to mark four 12mm holes that needed to be drilled in the framerails. Next, a small portion of exhaust heat shield had to be removed for clearance. (See green lines.) Next, a bracket was installed around the lower shock-mounting points and axlehousing. This bracket provided a landing pad for the Jounce Shock cylinder while at the same time protecting the OEM shock mounts. This setup is slick because it can't be installed incorrectly, and it provides much-needed protection to the lower shock mounts.
It was much simpler to install the Jounce Shocks on the rear of our donor truck. First, a

This illustration demonstrates how the rear Jounce Shocks work on the 1/2-ton GM kits from Light Racing. The 1/2-ton kits differ from the 3/4-ton kits because they use a sheetmetal rocker arm to align the Jounce Shock cylinder with the axlehousing. This system also works exceptionally well and has little or no effect on ground clearance.
This illustration demonstrates how the rear Jounce Shocks work on the 1/2-ton GM kits from
At 35 mph over a section of small roller whoops: Before installation, notice how our donor truck bottomed out shortly before the camera's shutter opened. The dirt forced up in front of the air dam is evidence of this. Also note the angle of the truck, front to back, relative to the ground. This is the natural reaction of the stiff rear OEM suspension forcibly bouncing the rear of the vehicle upwards.
At 35 mph over a section of small roller whoops: Before installation, notice how our donor
At 45 mph over the same section of whoops: Though not exactly in the same location as the previous picture, it is close enough to draw some conclusions. Notice how the truck, now with Jounce Shocks installed, is sitting level with the surface of the ground. This is because the OEM suspension didn't have to absorb as much force. Instead, the Jounce Shocks played an effective role in damping the compression caused by the whoops. In print, it is not easy to demonstrate how effective the Jounce Shock system is. However, the real-world benefits of the Jounce Shock system are easy to feel. We recommend this system to anyone interested in going fast in the dirt.
At 45 mph over the same section of whoops: Though not exactly in the same location as the