The OE suspension on new 4x4 trucks is the single most serious limiting factor when it comes to real four-wheeling performance. So it is with our '99 Dodge project vehicle, the Baja Bomber. We needed stronger suspension components, with a bit of lift to allow fitment of 35-inch rubber. But there's more. The Bomber is intended to be a true multipurpose truck. We intend to take advantage of the Cummins turbodiesel's torque to tow heavy loads when required. And on race day, we'd expect the truck to run competitively in the fast-growing diesel drag-racing circuits. It's safe to say raising the center of gravity was not an option. Was this too much to ask? Well, yes, it was, at least from a traditional lift kit.
We were stumped, and then we discovered T-Rex Engineering of San Diego. T-Rex offers a Baja-derived system available for all three generations of Dodge Ram trucks. T-Rex suspension systems don't change the OE suspension geometry, yet they significantly increase wheel travel. What they do change, however, are the dynamics by which the suspension works. Instead of using only the springs to absorb impacts, the T-Rex system adds hydraulics precisely tuned to the vehicle, just like a trophy truck suspension does. The result is a desert-friendly system that retains the design life of an OE setup. Follow along as Rock Star Trux of San Jose, California prepares the Baja Bomber for lift-off.
This is the complete T-Rex...
This is the complete T-Rex system. We opted for the Fox Racing Shox-equipped version. King shocks also are available. Notice there is no drop pitman arm, no alternative Panhard rod or longer control arms. This is because the system does not deviate enough from the factory geometry to require them.
The first step in the process...
The first step in the process was to remove the rear factory leaf packs, shocks and rear antiroll bar. Next, the upper and lower overload leaves are removed and replaced with the T-Rex minipacks. The system includes all necessary hardware to reconfigure the leaf packs.
Note the differences between...
Note the differences between the OE shock and the Fox remote-reservoir unit. These longer-travel shocks employ pressurized nitrogen to help absorb energy. The 71/48-inch-diameter shaft is significantly stronger and has a greater range of motion than the OE shafts. The added oil capacity helps combat heat-related shock fade.
Mounting the Fox shocks is...
Mounting the Fox shocks is a very simple process as long as the nitrogen reservoir is empty. The shock can be mounted in either direction, but if mounted with the reservoir up, some Rams required slight grinding to allow enough clearance between the massive 211/42-inch shock body and the frame.
Mounting the Fox shocks is...
Mounting the Fox shocks is a very simple process as long as the nitrogen reservoir is empty. The shock can be mounted in either direction, but if mounted with the reservoir up, some Rams required slight grinding to allow enough clearance between the massive 211/42-inch shock body and the frame.
This shows the rear shock...
This shows the rear shock during full suspension compression. Notice how much stroke is still available; this is what enables a controlled landing after a jump. The range of motion is nearly 50 percent greater than the OE setup.
This is the new anodized aluminum...
This is the new anodized aluminum shock mounting tower, which is CNC-machined from a chunk of 6061 billet aluminum. This is the secret to the T-Rex system; the tolerances on this part are critical to its function.
Up front, the steering, track...
Up front, the steering, track bar and upper control arms must be removed from the front axle as a first step. This allows for the removal of the old coil spring and shock. Once they are out of the way, a small amount of the plastic inner fender lining must be trimmed to allow room for the new anodized aluminum shock-mounting tower. Once the tower is in place, the remote reservoir must be fed through an opening in the side. A stud ring can then be fitted to secure the shock tower in place. Next, a new longer progressive coil spring is installed on each side. Once both coils are in place, the axle can be reconnected to the upper control arms as well as the steering and track bar. The lower shock mount is then secured to the axle.
With the suspension at full...
With the suspension at full droop, the optional limit straps are installed. This is the only step in the process that requires welding. These straps prevent the shocks from topping out when the wheels leave the ground.
Finally the last step in the...
Finally the last step in the process is to drill pilot holes to mount the remote reservoirs to the frame. After mounting these units with the supplied hardware, all four of the reservoirs must be filled with nitrogen. With the T-Rex system installed, we were able to fit a set of 35x12.50x18 Toyo Open Country M/Ts on 18-inch aluminum Weld Racing EVO wheels. The wheels and tires are available through T-Rex Engineering. You can also get a package deal with the T-Rex suspension system, Toyo tires and Weld wheels at select Dodge dealerships throughout California.
Testing
The T-Rex system was designed to allow jumping. Here in the paved confines of L.A. this can be a hard thing to find. We asked Kent Kroker, the owner of T-Rex, where he suggested we go. His answer surprised us. "Lets run the Baja 500 race course this weekend," without hesitation. We couldn't find a better answer, so on the next Friday we headed south to the wild countryside of Baja, Mexico. Along the way the T-Rex kit surprised us with its pleasing road manners. Smaller bumps seemed to completely disappear, and larger ones felt tiny. This velvety response to the road imperfections seemed like the hot ticket for stiff-suspension 31/44-ton trucks. The new progressive coil springs up front responded to bumps much faster than before. The 211/42-inch Fox remote-reservoir shocks created a rollercoasterlike feeling of stability with only a few degrees of predictable body roll.
Once we were comfortable with the truck's new dynamics, we found a place to catch air. We took it easy at first, and then as our confidence climbed we took the jump at around 50 mph. We launched the truck up in the air 3 feet and just as we expected, the suspension soaked up the landing without even bottoming out. So the ride quality was improved, and we could even jump now, but what did we sacrifice in heavy-hauler functionality? To test this, we decided to tow Teal-J to Moab for the annual Easter Jeep Safari. The truck felt stable at all times. We carved confidently into corners wishing a jump or two lie ahead.
The final test for the T-Rex system was Moab's Hell's Revenge trail, with its steep inclines and off-camber stair steps. The increased suspension travel and better approach and departure angles made negotiating the slickrock a breeze.