Jerrod Jones
Former Editor, Off Road
Dodge Rams are great trucks, and the 2500 and 3500 models are available in front solid axle configurations. Better yet, they ride and handle nicely in the dirt when modified. They even come with an available Cummins diesel engine, giving them gobs of torque for lots of fun off-road play.
But while the front solid axles are strong enough to handle day-to-day street duties, the AAM axles aren’t quite robust enough to handle vigorous (read: airborne) off-road adventures in the dirt—especially when outfitted with a heavy diesel engine.
So, without going completely custom to replace an axle that has ABS sensors and possibly factory lockers, your next best step (and much more economical one) is to reinforce what’s already under your truck.
The Carli Suspension axle truss showed up in a single box with gussets and tube saddles packed inside. It’s a do-it-yourself weld-on truss, so expect to do a little finessing with a grinder and welder.
Carli Suspension, makers of premium Dodge suspension components quickly learned that once they built kits that allowed Dodges to start moving faster off pavement, the front ends were bending at an alarming rate.
Enter the Carli fabricated axle truss kit. It gives the front ends of 2500 and 3500 4x4 Dodges a much better chance of surviving the rigors of extreme off-road use under the heavy front end of a truck. It’s not a “direct fit” item, meaning that you’ll have to do some grinding and welding to make everything fit together, but that should be expected with any custom axle kit that requires some fabrication.
We went to Mercenary Offroad in Camarillo, California to watch them weld a truss onto the front end of a 2005 Ram 2500 with 41.5-inch Pit Bull tires. Extremely heavy tires combined with a Cummins diesel engine and rigorous off-road use left this axle aching for some bracing, which it got in the form of a Carli axle truss.
Don’t get confused by these plates tack welded onto the ends of the truss. They’re for shipping purposes only—so the sharp ends of the truss don’t cut through the box and fly out of the packaging. Knock these off with a grinder or hammer.
While some guys do weld axle trusses on while the axle is still under the truck, Todd Farrand of Mercenary Offroad removed it and stripped the housing down. He also cleaned the metal of the housing well before starting. Common beliefs state that you should weld the truss on, with weight on the axle, if it’s perfectly straight and unhurt. But, if the axle is bent (upwards, most likely from impact, leaving your tires angled in at the top), there is the potential to bend the tubes back down a bit by welding the axle unloaded, out of the truck. If everything goes as planned, the metal housing will pull towards the truss as it’s welded, and you’ll fix your caster issue.
The Carli fabricated axle truss is made out of ¼-inch plate cold rolled steel and has X-bracing and reinforcement ribs that add to the strength of the truss. Tube saddles sit inside and perpendicular to the truss so the truss is welded to the tubes in more than one direction, further improving strength.
PhotosView SlideshowThe Carli kit comes with gussets for the upper and lower parts of the inner Cs of the axlehousing. This is also another weak point for the Dodge AAM front axles. If the tubes don’t bend (or stop bending), then the inner Cs will be the next to fatigue. Carli’s kit makes sure to address both the front, back, top, and bottom of the inner Cs.
Without starting a huge debate on how to weld to certain metals and what types of material to use, we’ll tell you that Farrand used nickel rod to weld to the cast differential, after he heated it up, and then let it cool after each pass. He used stainless rod on the inner Cs, after also heating them up.
Since Mercenary Offroad pulled the axle out of the truck, it gave Farrand the ability to flip it over and make work on it much easier. No one likes to weld overhead and upside down. As he welded the kit together, Farrand made sure to keep the truss squeezed as tightly as possible to the housing.
While Mercenary Offroad was successful getting their welds to stick and not crack, be aware that welding to the inner Cs and cast centersection can be tricky. Make sure to check for minute cracks that might appear along the welds as the metal cools. If you see cracks, grind out, figure out what was wrong, and start again. If you don’t have practice welding to material like this, we suggest letting a more experienced welded help you out.
Ground clearance is diminished a bit with the Carli axle truss installed, but that’s not an issue to the vast majority of Ram owners who will never use their trucks for extreme rockcrawling where the differentials could be hung up.
You can see why a Carli fabricated axle truss was sorely needed on this Ram 2500. Even with the truss installed, the 9.25 AAM axle still looks a little puny in between the massive 41.5-inch tires.
