Ram 3500 HD Adds Beef, Power

Sept. 28, 2010


Ram 3500 HD Cab Chassis can shoulder much heavier loads than the 4¾ yards of topsoil-mulch mix it carried in its dump bed this day. Dull grey nose says "work truck," but it's also a joy to drive. Will this chassis be the basis for heavier-duty models? Dodge isn't saying.
A/C condenser, intercooler, transmission oil cooler and radiator are stacked ahead of the engine. The 6.7-liter Cummins Turbo Diesel is quiet, strong and odor-free, and its variable-geometry turbo doubles as a strong retarder.
The rear frame has stout, 50,000-psi, straight-through rails spaced 34 inches apart for easy body mounting, as with the Knapheide dump box and electric-hydraulic hoist on this truck.
A roomy Regular Cab with base ST trim can seat three and stow stuff behind its Vinyl-covered bench seat. Gauges and controls are legible and easy to use, and the handle on the A-pillar helps shorter drivers climb in.
Test Set


Truck: 2007 Dodge Ram 3500 Heavy Duty Cab Chassis, conventional Regular Cab, BBC 122.9 in., GVW rating 12,500 lbs. w/dual rear wheels, GCWR 23,000 lbs.

Engine: Dodge-Cummins Turbo Diesel, inline 6-cylinder, 6.7 liters (409 cu. in.), 305 hp/610 lbs.-ft., w/exhaust brake and exhaust aftertreatment

Transmission: Aisin AS68RC 6-speed automatic w/overdrive 5th & 6th

Front axle: 5,200-lb. American solid-beam on 5-link coil springs w/link-type anti-sway bar

Rear axle: 9,350-lb. American solid-beam on 2-stage leafs, w/link-type anti-sway bar;4.10 ratio

Wheelbase: 167.5 inches

Brakes: 4-wheel discs w/ABS

Fuel capacity: 52 gallons

Body: 4/5-yard 11-foot Knapheide steel dump w/electric-hydraulic hoist

Do you run a Chevrolet/GMC 3500 or a Ford F-350? Then Dodge wants you to take a look at its latest Class 3 model, the Ram 3500 Heavy Duty Cab Chassis. It's a lot more truck than the "box-off" version of the current Ram 3500, and seems well set up to grab a bigger share of this 100,000-unit-per-year market.

Though executives won't confirm it, Dodge appears poised to expand upward in the weight classes, and this 3500 HD could easily form the basis for 4500 and maybe 5500 models. Dodge left the medium- and heavy-duty sectors more than 30 years ago, and returning to Class 4 or even 5 would suit its parent, DaimlerChrysler. DC also owns Freightliner, Sterling and Western Star here and Mercedes-Benz in Germany, and thus is the world's largest builder of commercial trucks

For now, the new 3500 HD Cab Chassis is a lot of truck. Its rear frame is noticeably beefier than lesser-rated Rams; rails are spaced 34 inches apart, the standard for medium- and heavy-duty trucks in North America, for easy mounting of work bodies. Its GVW rating of 12,500 pounds is 1,000 pounds more than heretofore available from Dodge. And it has the optional Cummins Turbo Diesel, which is bigger, more powerful, and cleaner burning for 2007.

About two-thirds of people who buy heavy pickups get a diesel, and Dodge customers have good reason to pick a Cummins-powered Ram. Since its introduction in the 1989 model year, it's built a reputation for power, economy and long life. Big-rig styling applied to Rams in '93, along with many cab and chassis refinements since, have made the Dodge-Cummins combination even more magnetic.

For years, the Turbo Diesel has been a variation of Cummins 5.9-liter (360-cubic-inch) ISB, an inline Six instead of competitors' V-8 diesels. The I-6 configuration is what big-rig diesels all have, and that's part of its mystique. The '07-spec engine has a bigger bore and stroke for a displacement of 6.7 liters (409 cubic inches) and many other changes. Among them are more powerful electronic controls and enhanced combustion and aftertreatment equipment in the exhaust system. Dodge says it's keeping the '07 diesel option at the current price of $5,605, whereas most others are raising it by $1,500 or more.

The new Turbo Diesel emits no smoke or odor. With it idling in this truck, I bent down to get my nose close to the tail pipe, and the gas coming out smelled like the engine was burning propane. Of course, it's burning ultra-low-sulfur diesel fuel, and any owner must be sure to use only that or the oxygen catalyst and particulate filter in the exhaust can foul up. It's an expensive thing to replace.

Yanking off the aftertreatment device and putting in a big-diameter straight pipe to get a macho bellowing, as many enthusiasts have done to their Turbo Diesels, will not be allowed. The filter and everything upstream must stay on the truck and be working to stay legal; if someone removes it, he'd have to disconnect sensor wires, and this would render the engine inoperative. However, downstream is a muffler that could be removed without breaking any laws or adversely affecting exhaust quality. And it might put some bark into the sound.

As it is, the engine makes some nice exhaust and mechanical sounds. And its performance will keep any sane person happy. Even slightly derated to a commercially sensible 305 horsepower and 610 pounds-feet as it is in the 3500 HD (versus 350/650 in lighter-duty Rams), the Cummins 6.7 propels the truck briskly. Under load, the turbo whines faintly and the engine pulls strongly.

Under load, too, is when the engine's exhaust brake is most useful. You switch this on with a dash-mounted push-button. Take your foot off the accelerator and it begins retarding; downshifting to raise revs results in more retarding power, and it even sounds like a Jake Brake. As I approached one stop sign, a work crew about a hundred feet away paused to watch and listen to the retarder work; I bet they wished they had one in their pickup.

The exhaust brake is actually the variable-geometry turbocharger that adjusts to restrict gas flow. It's said to be 35 percent more powerful than a butterfly valve-type exhaust brake. The turbo is ready to work as a retarder; all it needs is the electronic control package, which the factory installs when the buyer or dealer chooses the exhaust-brake option.

The Cummins seems ideally suited to the new 6-speed Aisin automatic. During acceleration, the transmission shifted smoothly and often enough to usually keep revs between 1,500 and 2,000 rpm, even with moderate pressure on the pedal. The Cummins pulls nicely at those speeds because it's developing most of its torque down there. It's very satisfying to operate.

The transmission's shift quadrant is at first disappointing because it reads P-N-D-3-2-1. There's no 5 or 4 position to pull it out of 6th and 5th to make best use of engine braking on long downgrades, or to hold it in one of those gears while climbing. Didn't the Dodge Boys think this through? Actually, yes.

There's a push-button on the lever's end: Tap it once with your index finger and it engages Tow-Haul Mode, which sets the transmission to automatically downshift when the retarder is on; push it again and it switches to Overdrive Off, which locks out the top two gears. This works better than it might sound, and might be less clumsy than trying to manipulate the lever among more positions. Tow-Haul didn't seem to affect upshifts during acceleration, but the Cummins is so gutsy that it almost didn't matter what gear the tranny was in.

Sixth-overdrive has a 0.63 to 1 ratio and 5th-overdrive's is 0.77 to 1. These provide some pretty long legs, even with the rear axle's 4.10 gearing, and top gear especially keeps revs low at highway cruising speeds. The tachometer shows a redline of 3,500 for the engine, but it should seldom get above 2,500 rpm unless you hold the tranny in lower gears just for the silly fun of it.

The standard transmission in the 3500 HD and most other Rams is a 6-speed manual, but most folks will choose an automatic. Standard engine is the Hemi gasoline V-8 mated to the manual or a 5-speed automatic. This engine makes 25 more horsepower, but a little more than half the torque of the commercial-spec diesel. Once you drive the Cummins, you might not be satisfied with anything else.

The diesel will get better economy and last longer, but you'd have to weigh those savings against other realities. Look at the diesel's $5,600 upcharge and diesel fuel's 30- to 50-cent-a-gallon higher price compared to 87-octane gasoline, and that gasser V-8 begins making business sense. And hey, it is a Hemi.

Anyway, the truck as a whole was a genuine joy to drive. It handled well, with easy and steady steering and flat cornering. With the box empty, the ride was firm but not harsh; with a load aboard, the ride softened a bit, just as you'd expect. The Cummins rumbled enough that I never forgot it was there, yet the interior remained quiet and, with windows up, was insulated from most road noise.

I used the truck to haul some dirt. With sides 1 foot high and no extender boards, the 11-foot-long Knapheide dump body was able to carry about 4-3/4 yards of topsoil that my wife and I used to fill in some low spots in our backyard. The box's "virgin" paint didn't let the soil slide out, but raising the body let me pull it out easily with a shovel. The electric-over-hydraulic hoist worked smoothly, and its controls were the simplest I've ever seen: Buttons on a tethered box said Up or Down, period, and there was no "body up" warning light.

Dodge designers upgraded the Ram's interior a couple of model years ago, and it's pleasant, even with the base ST trim this one had. Large expanses of grey plastic covered most of the interior surfaces and the bench seat had patterned Vinyl covers; I'd opt for cooler cloth seats. The seat had a large center fold-down arm rest; with more upscale trim, this becomes a box with lots of storage room.

The Ram Regular Cab is wide enough for three big people. It's long enough for a 12-inch-deep by 55-inch-wide plastic tray behind the seat, so small tool boxes and other stuff can be stowed there. The floor is about 2 feet off the pavement, so climbing in was not a big chore.

Outward visibility is great through big power side windows, the manually extendable mirrors, and through the huge windshield. The windshield slopes steeply to reduce wind drag, but that makes it hard to clean inside and overnight moisture and dust collects outside.

So, you just read my only gripe about the Ram 3500 HD. This is a fine truck with good driving manners, a smooth ride, a high fun quotient, and plenty of capacity for work. I don't haul enough topsoil or anything else to need a vehicle like this, but if I did...