Project LBMC: Kelderman Air Ride

December 2012 Spotlight

You may recall our project LBMC (Long Bed Mega Cab), a 2007 Dodge Ram 3500 DRW Mega Cab that's got so many aftermarket upgrades and enhancements; we're having a hard time finding a nook or cranny to add anything else to it. We started this project with just 97 miles on the odometer, and now with over 118,000 miles on the clock, it's probably the longest-running magazine project truck with continuing coverage in the industry. We've been running 22.5-inch Alcoa rims and 16 ply tires for the life of the truck, as we're a little tired of the stiff ride that the commercial wheels and tires provide. We love how bulletproof they are and their stability under a heavy load, but they provide a pretty rough ride, especially when running the truck empty, and we've been meaning to upgrade the suspension for the last 50,000 miles.

We decided to run Kelderman's 4-Link Rear Suspension, which will replace the factory suspension with an auto-leveling four-link model that will allow the truck to ride on two large air bags. This suspension kit will give us increased load capability, while producing a more comfortable ride under any condition, loaded or unloaded. The LBMC will auto-level under any load and on any surface. It will also allow the truck to lower the rear end or "kneel," which will make the mundane task of hooking up a trailer much easier on us, as well as make it a parlor trick that will impress any onlooker. We're also going to get the optional air dump with our kit, so when we hit large bumps or the suspension gets a heavy jolt, the airbags will be able to release air quickly for an even better ride. In this article, we'll walk you through what it took to install this kit.

Diving In

Kelderman has air ride kits for a variety of makes and models, including the LBMC, which utilize the same kit as a regular cab long bed or a crew cab long bed. As soon as the truck had a couple of days off it went back to Precision Bodyline in North Salt Lake, Utah, for the work. They started by removing the bumper and bed.

After the bed was removed, the location of the rear axle was measured to assure that everything went back to where it needed to be, and the distance from the cab and pinion angle was noted. Next, they blocked the truck up so that the axle and leaf springs could be removed from under the truck's frame. We decided to completely remove the axle so that we could show the install of this kit in better detail; however, it is not necessary to completely remove it.


With the axle removed, we started the install of the Kelderman air ride. The large control arm brackets mount directly to the front leaf spring mount with bolts and a few welds. Then they mounted the control arms and air bags to the axle mounts, and then to the axle.

After the mounts were in place on the axle and frame, the axle was then put back under the truck and the control arms were bolted to the front mounts. The truck was then lowered back down so that the proper distance from the cab to axle and pinion angle could be set, and the track bar was installed. The side-to-side was set so the axle was centered with the frame. The main air tank and compressor were installed inside the frame and the air lines were run from compressor to the air tank which then went to a control valve that was electronically controlled by switches in the cab of the truck.

The wires were run for the auto leveling sensors that mounted to the front control arm brackets. After the air lines and wiring were done, the bed was ready to be placed back on the truck and the Kelderman kit was ready to set up for the ride height.

Testing It

After setting the desired ride height, we were then ready to start our testing of LBMC's new Kelderman air ride kit. We took the truck out and drove it for a few days, and noticed the ride was greatly improved. Then came the towing.

One great feature that this kit has is the ability to drop the truck and raise it in the cab, which is perfect

for people who tow a lot. When backing up to a trailer you can drop the rear of the truck, back under the trailer then raise the truck back up, and there's no need to fight with the trailer jacks as much. If you have spring loaded or adjustable feet on your trailer you can simply raise the truck to max height, set the feet, drop the truck as low as it will go and pull out from under the trailer. This is far less messing around with loading and unloading of the trailers. Before the install, when towing, the truck would jerk or have a tendency to feel as though it was lunging if you hit a bump in the road. After the Kelderman was installed, we noticed that LBMC no longer had that lunging feeling. The truck handled better with and without a load and no longer felt like you were driving something that required a kidney belt to drive. This was a great upgrade for project LBMC.

Overall we should have had Precision Bodyline do this upgrade when they did the long bed conversion. It would have saved a lot of headache, back ache and Advil. This is just what we needed on this truck.

Kelderman Manufacturing

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