CARLI DIESEL SUSPENSION
A CARLI SUSPENSION HELPS THIS RAM GO PLACES
The top-notch lift system this 2018 Ram 3500 Cummins needed.
CARLI SUSPENSION ISN’T JUST something you stab under your truck’s framerails to fit bigger tires and look cool rolling into the mall. Carli actually engineers its suspension systems, with specially designed applications for Dodge, Ram, and Ford trucks that ride killer, increase wheel travel, and retain on-road drivability and hauling capability without sacrificing off-road performance.
When it came time for the owner of this 2018 Ram 3500 Cummins with the Aisin six-speed transmission to improve the suspension, Carli offered a top-notch lift system to meet its needs. The plan was to build a crawler/hauler/daily-driver/work truck that could go reasonably fast in the desert, crawl rocks, and serve as a recov-
ery and trailer-hauling rig. It’s a tall order, a pickup that can do it all.
Carli offers four 3-inch suspension systems: Leveling, Commuter, Backcountry, and Pintop. For this truck the Backcountry system was used since it improves not only off-road performance but also highway ride. New coil springs and full-replacement Deaver rear leaf packs, along with applicationtuned Fox shocks with remote reservoirs, make for a complete package.
To retain good front suspension geometry with the added lift, Carli provides new brackets for the frame to drop the rear attachment point of the radius arms. The plan was to go from the stock 34-inch-tall tires to 37-inch ones. As such, we also used a set of Carli radius arms that are much beefier than stock, use a spherical joint at the frame end, and are angled inward on each side to allow for greater tire clearance at full steering lock.
The Cummins-powered trucks come with a fat torsion bar from the factory that severely limits front axle articulation. It can be retained with the Carli lifts, but we opted to use Carli’s torsion sway bar because it’s tuned to allow the axle to move more freely from the chassis, improving ride quality and trail flex. The lift kit also includes an adjustable front track bar, plus bumpstops and limit straps to protect the Fox 2.0 reservoir shocks under full bottoming and droop conditions. In addition, we added a Carli high-mount steering stabilizer to supplement the stock unit. The radius arms and track bar come preassembled with spherical joints, and Carli provides detailed instructions for the kit build.
The lift was installed at Lamb Fab in Gilbert, Arizona. With two guys working with the truck on a lift, the install was completed in one day. In general, only common mechanic tools were needed, with the exception of a right-angle drill for making some of the holes in the frame. Two limit strap brackets do require welding at the frame. We estimate the lift could be installed in a home driveway over a weekend with two people, given the amount of work needed and the weight of some of the parts.
With the rise in height and fender clearance, it was time to mount some new rubber to the Ram. The truck now turns 37X13.50R17LT Toyo Open Country R/T tires. These are an aggressive all-terrain-type tire designed to provide solid off-road traction combined with comfortable highway ride and handling. The 37-inch tire is a D-rated tread with a load rating of 3,195 pounds at 50 psi.
The new suspension felt firm at first, but after some trailering and a good trail run the springs set in and softened. After a month they keep getting better. With the lift and larger tires, the approach angle was improved by about 8 degrees and departure angle by about 4 degrees. Axle ground clearance went up 11⁄2 inches due to the increase in tire height. The truck rides well both on the highway and off-road. The suspension feels like it wants to roll fast through whoops, and soaks them up cleanly. The truck still tows well while also flexing better in the dirt. The Toyo R/T tires turned out to be a great fit for this project. They are very quiet on the highway, feel stable, and still provide solid traction under most trail conditions we should encounter. Overall, the choice of lift combined with upgraded tires greatly improved the performance of this diesel Ram.
Carli offers several different kits for this application to address the needs of most drivers. In this case, the company’s 3-inch Backcountry system satisfied our use goals and made way for fitment of 37-inch tires.
2 With the truck up on a lift, disassembly of the front end began with removal of the front sway bar components, shocks, coil springs, and bumpstops. It pays to be thoughtful about where you place the lift pads or jackstands because you need access along the frame to install the new radius arm mounts.
3 Each factory radius arm was removed from the frame and the axle mount points. For the larger suspension pieces, it helps to have a second person to move the parts in and out.
4 With the front axle drooped, it was a good time to pull off the factory rubber bumpstops. It’s necessary to drill a hole in each frame mount to allow installation of the Carli drop mount. Here’s where that right-angle drill we mentioned can come in handy.