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2008-2010 Dodge Ram 4500 and 5500 Chassis Cabs

Dodge left many markets in the 1970s, as it focused resources on survival of its car business. Heavy and medium-duty trucks were among the casualties - but, decades later, the company decided to return, with a series of chassis cabs, reportedly developed with engineers from what is now Daimler Truck North America. The trio of chassis cabs (3500, 4500, 5500) started to pose a serious challenge to GM and Ford, the market leaders.

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Among the advantages of the Dodge Ram series were a smooth-topped frame which made it easier to mount aftermarket beds, powerful long-lived brakes, comfortable cabins, and of course the Cummins diesel option.

From the outside and the cabin, the big medium-duty Dodges looked like Ram pickups, keeping the trip computer and ability to set headlight and internal power-off delays. The big differences were underneath, with a special frame, 7,000-pound-capacity axle (1,000 pounds more than the standard Ford axle), and extra power lines wrapped around the end of the frame.

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According to the independent Transportation Research Center, the 2008 Ram 4500 and Ram 5500 had 23% better gas mileage than the Chevy Kodiak/GMC Topkick, 14% better than the Ford F-550 Chassis Cab (20.2 mpg overall).

In 2007, Dodge had a 21% total retail market share for Class 3-5 trucks, led by the 3500. In 2009, despite a depressed market, Dodge sold 8,006 Ram Chassis Cabs - a decent number for the class. Dodge wasn't in the lead for #1, but they were making a dent.

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Allpar spoke with Chrysler communications specialist Randy Jones and engineer Jim Repp ("Engineering Supervisor, Vehicle Development, Body on Frame Product Team") to learn that the chassis cabs were a Dodge engineering project, even though Sterling sold a similar vehicle as the Bullet. The commercial Rams were built on the same assembly line as Ram 2500 and 3500 pickups.

In August 2008, Dodge sold around three times as many Ram Chassis Cabs as Sterling sold Bullets; then DaimlerChrysler dropped Sterling, and with it, the Bullet, at the end of the 2008 model year.

Powertrain

GM's TopKick 4500 used a gasoline V8 (325 hp, 450 lb-ft), or a GM/Isuzu diesel (300 hp and 520 or 605 lb-ft of torque), coupled to an Allison five-speed automatic or six-speed manual. Ford was less competitive in powertrain at the time, using Navistar diesels and less powerful gasoline engines.

The Ram 3500, 4500, and 5500 were engineered with durability and uptime in mind. Part of that was the Cummins diesel; the sole engine of the Class 4 and 5 (4500 and 5500) trucks. The Cummins was remarkably quiet, which we were told made them attractive to repo men; but it also boasted 350,000 mile life-to-overhaul intervals, best-in-class first-gear launches, and competitive power of 305 hp at 3,000 rpm, and 610 lb-ft of torque at 1,600 rpm.

The Cummins avoided add-on emissions equipment for some time, and was B5 certified - with the largest-in-class 52-gallon gas tank. All emissions equipment was under the cab, avoiding issues with upfitting.

The Ram 5500 we drove was surprisingly quiet outside; under heavy acceleration, it did make more of a racket than the Hemi-powered Rams. It was much quieter than the new Ford diesel we used for comparison.

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Dodge provided two transmissions, both typically used in Class 6 trucks: a six-speed Aisin automatic (also used in Kino-Toyota trucks), and a six-speed 656 manual sourced from Getrag. The Aisin came with a three year, 180,000 mile, zero-deductible warranty. In our test drive, it shifted quietly, smoothly, and correctly. The truck moved swiftly and easily when needed, and owners talk of feeling as though they could tow twice as much as the rated capacity - the engine wasn't the limiting factor.

An optional power take off (PTO) package had to be purchased with the truck, rather than as an add-on; it used a mechanical pump with a cable, or an LPN package including the ability to raise the idle speed.

Suspension and steering

The front suspension on the Class 3 Ram 3500 Chassis Cab was retuned and redesigned for the much higher loads of the Ram 4500 and 5500 (for example, the axle was lengthened by five inches for tighter cornering and better stability, and was beefed up to reach the standard 7,000 pound capacity). Both front and rear axles were both solid beam, with a five-link coil-spring front suspension up front and two-stage leaf springs in back. Tubular shocks and front and rear link-type sway bars rounded out the package.

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All the Class 4 and Class 5 trucks had dual rear wheels, with either steering or traction tires, or steering tires up front with traction tires in back. A low-friction recirculating ball system kept the wheel on-center. Upgraded power steering from the 3500 had a more precise feel and better handling.

suspension.jpg


Four cab-axle lengths (60, 84, 108 and 120 inches) were sold; the gross weight rating (GVWR) was 16,500 pounds for the 4500, 19,500 pounds for the 5500. The gross combined weight rating for both was 26,000 lbs. Payloads beat Ford's 2007 chassis cabs across the board.

rear-suspension.jpg


To increase uptime, the Rams had the largest front brake rotors (390 mm) and caliper pistons (66 mm) in the industry, along with a standard exhaust brake and (with the Aisin) a tow/haul mode that downshifted earlier. Dodge expected roughly double the brake-maintenance intervals from one rival. Four-wheel disc brakes with anti-lock braking (ABS) were standard.

The steering felt solid and precise, with a good feel: power assisted, but not overly so. The turning radius was good for a large truck. U-turns were not difficult, in either turning space or in manual steering effort; while highway travel was stable with a good on-center feel and easy control over the vehicle direction. The Ram chassis cab, with a Crysteel bed, was a pleasure to drive on the highway and on ordinary streets, responding instantly and predictably with a sense of stability. Braking was also easy, with a normal passenger-car brake feel and reaction, stopping straight and predictably.

Chassis and upfitter friendliness

James H. Repp, who worked on the truck's chassis and electrical systems, was once publicly ridiculed by Bob Lutz for the hands-free telephone system he had designed. Repp came back with a prototype and user surveys, and Lutz admitted that Repp was right after all. Now, Jim Repp works on the Commercial Vehicles Team with other engineers and Dodge employees to address issues and answer technical questions.

Since upfitters drive sales, they were at the center of the engineering effort. (Upfitters build the tow-trucks, dump beds, cow-flippers, cargo boxes, and such.)

The frame is stronger yet lighter than some competitors, using 50,000-psi steel; Dodge claimed it was over 38% stronger than
the Ford F-450/F-550 frame. It had standard 34-inch spacing, with flat, clean frame rails so minimal redesign would be needed - our test truck's dump-truck upfit was designed for a rival's pickup. All chassis components were below the frame surface.

The one-piece C-channel frame provided shear plate or u-bolt access along the length of the frame. Bolt-on and riveted-on exhaust hanger brackets increased upfitter flexibility, and riveted cross-members behind the cab allowed for easier modification (e.g. the addition of frame extensions).

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The gas tank had a tap to allow diesel fuel in the tank to be used for on-board generators; an optional mid-ship fuel tank underneath the frame rails freed up more space behind the rear axle if needed. Fuel and brake lines were routed together to make better use of space along the frame.

The electrical system was similar to the regular Dodge Ram, with some major exceptions. An overlay added three fused 30 to 225 amp wires starting under the hood, looping through the dashboard to allow for switches, and going all the way along the frame to the rear. A high-current 50-amp ground stud was on the rear of the frame. Back wiring included the third brake light feed, with three other feeds and a blank wire, and trailer tow wiring.

frame.jpg


Rollback Carrier package, Snow-Plow Prep package, Limited Slip Axles, and PTO Prep Packages were available. The snow-plow package included a one-up spring to compensate for permanent mounting of the weight up front.

To support the upfitters and end users, a new commercial vehicle group was formed with engineers from different disciplines. According to the Dodge people, when they held a session to discuss the new trucks, a 600-seat room was filled to standing room only; that's a good sign for the future.

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Durability and testing

Dodge claimed 1.5 million test miles on these vehicles; more importantly, Jim Repp talked about their efforts to find and fix problems. He said "we did some pretty crazy stuff" to the vehicles internally; and Dodge lent 30 trucks to customers, looking for the worst possible customers who would use and abuse the vehicles more than most. This included a utility that had trucks in use 24 hours a day laying cable, and a New York City wrecker.

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At the end of the trial, participants were allowed to buy their trucks from Dodge; and the only ones who didn't were some of those with the gas engine, who wanted to switch to the diesel. The Ram 4500/5500 trucks had, at the time of writing, only been out for around three months, but Repp said there had been no problems in that time, despite the harsh duty cycles.

Chassis Cab Issues

Keith K. wrote that the circuit board in the door of the Ram - the passenger door module, which handles power locks/mirrors/windows, is bolted right behind the door panel. On the 2010-2011 chassis cabs, a few driver's door modules have issues with water leaking in and directly onto the connectors of the door module, and killing the interior (CAN.-IHS) bus. The repair is a new door harness and module, then sealing the connectors so they don't corrode again. "I think it affects chassis cabs mainly cause the windows are left rolled down a lot while the driver is out of the truck (truck idling) in the rain."

Dodge Ram cabs and styling

evic.jpg


Twin, large 7- x 10-inch towing mirrors could be folded back in (see our video); visibility was further enhanced by low door sills and sun visors that slide out on extensions when needed to cover the full windshield.

The Ram 4500 and 5500 Chassis Cabs were available with regular and four-door cabs, in ST, SLT, and Laramie trim, with rear and four wheel drive.

4500-interior.jpg


Leather seats were available with vinyl floor mats or carpet; they were attractive and large, but too firm and stiff for us. Driving was pleasant in terms of ride and noise. The stereo was a standard corporate unit with good sound and stereo separation, though perhaps with somewhat boomy bass; in our test Ram 5500, treble, bass, and midrange could all be adjusted (as far as we can tell, we had the base stereo, which includes a CD player). Our test truck had a moderately full gauge set, lacking only a transmission temperature gauge; we had cruise control, a manual 4x4 control (an electronic 4x4 control is optional), and manual locks and window cranks. The glove compartment was fairly small but there was a decently sized storage bin stretching across the entire cab behind the seats, a plastic/rubber tray with roughly four inch edges to keep things in place.

storage.jpg


Quad Cab models have six passenger seating, with four standard doors and 60/40 folding rear seats. Seat cushions fold up to create a tall storage area from floor to ceiling. An optional floor section under the back seat folds open to form a flat-load floor with additional storage in each of the foot wells. Regular cab models provide generous storage behind the rear seat.

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Dodge Ram chassis cab production and flexible manufacturing

The Dodge Ram 4500 and 5500 Chassis Cabs (Class 4 and Class 5) were built at Chrysler's Saltillo Assembly Plant in Coahuila, Mexico, which also produced every other Dodge Ram model except the 1500 on the same lines - without an appreciable delay to change models.

chassis-cab-inside.jpg


Adding the new trucks to the plant cost about $48 million, following a $210 million investment in 2005 to produce the Mega Cab; adding 120,000 square feet to the plant allowed for new frames and the building of commercial vehicles. One of five Chrysler plants in Mexico, Saltillo has 2,100 employees working on two shifts.

Buying Class 4 and Class 5 Dodge Ram chassis cabs: Dodge BusinessLink

Around 55% of the Class 4 and 5 chassis cabs were the Dodge Ram 5500. Roughly 80% of buyers opted for an automatic transmission; around 70% for the lower ST price class. The regular cab accounted for around 65% of sales. Sales were split nearly in half on 4x4 vs 4x2. (Information appears to be from 2008.)

The Ram 4500 started at around $34,000 and the 5500, at around $36,000. The Class 4 and 5 markets (140,000 vehicles sold in the US in 2006) were dominated by General Motors, with a 53% share, and Ford, with a 40% share.

5500.jpg


Test truck notes

Our test truck was a 2008 Dodge Ram 5500 ST chassis cab with a Crysteel bed, 13,500-pound capacity 4.88:1 rear axle, and four wheel drive. Options included the heavy duty vinyl 40/20/40 split bench seat, overhead console with trip computer and EVIC (pictured), bright front bumper, air conditioning, automatic, airbag shutoff, snow-plow prep group, mini floor console, PTO preparation, cruise, auxiliary oil cooler, and engine block heater. It had a 160 amp alternator, and the speedometer went up to an unreasonable 120 mph. The interior was a pleasant tan color, and the bright bezel around the center stack was a good dress-up touch.

2012-chassis-cab.jpg


2008-2009 model year changes

The 2009 Ram Chassis Cab (4500/5500) had an exterior label to bypass idle limits in ARB states. Dodge added an ambulance prep package, and increased the PTO pump rating by 55%. The automatic-transmission 6.7 engine now came with remote start, and cruise control became standard (with an optional delete). Dodge confirmed that front brakes lasted three times longer, and rear brakes lasted four times longer, than comparable Ford brakes; the Ram was certified for a 1,172 pound payload advantage over the Ford F-450 and F-550.

The 3.92:1 axle ratio was now standard on diesels for better gas mileage.

dodge-tow-truck.jpg


For 2010, new options included a 22 gallon mid-mounted fuel tank, khaki interior, new bucket seats, six-disc CD player, light group, new navigation system, and 108 inch cab-to-axle; the Laramie price class was changed and the electric-shift transmission case was changed.

The 2011 Dodge Ram Chassis Cabs had many changes.

Specifications: Dodge Ram 4500 and Ram 5500 Chassis Cabs

All dimensions are in inches (millimeters) unless otherwise noted.
All dimensions measured at curb weight with standard tires and wheels.


Engine: 6.7 liter Cummins straight-six intercooled turbodiesel

Displacement408 cu. in. (6690 cu. cm)
Bore x Stroke4.21 x 4.88 (107mm x 124mm)
Valve SystemOHV, 24 valves, solid lifters
Fuel InjectionElectronic high-pressure common rail
ConstructionCast-iron block and head
Compression Ratio17.3:1
Power (SAE net)305 bhp (227 kW) @ 2,900 rpm
Torque (SAE net)610 lb.-ft. (827 N•m) @ 1,600 rpm
Maximum Engine Speed3,500 rpm
Fuel Ultra-low Sulfur Diesel; B5 certified
Oil Capacity(Low ash req.) 12 qt. (11.3L) with filter
Coolant Capacity32.7 qt. (30.9L)
Emission ControlsOxidation catalytic converter with aftertreatment system
Electrical220 amp alternator; dual Group 65 750 CCA batteries
Transmissions

ManualGetrag
six-speed manual
Aisin AS68RC
six-speed automatic
PTO Capable Standard mounting, L/R mounting, 35 HP max
1st Gear 5.943.74
2nd Gear3.281.96
3rd Gear1.981.34
4th Gear1.301.00
5th Gear1.00.77
6th Gear0.74.63
Reverse5.423.54
Notes Synchronized
in all gears
Electronically controlled
overdrive lockout,
converter clutch
Overall Top
Gear Ratio
2.42 with 3.73 axle ratio
2.67 with 4.10 axle ratio
Transfer Cases : NV273, NV 271 (standard on 4x4 models)

TypePart-time
Operating Modes2WD; 4WD High; Neutral; 4WD Low
Shift MechanismNV 273 - electric, NV 271 - manual
Low-range Ratio2.72
Center DifferentialNone
Dimensions and capacities

All Models

CabRegular Cab Quad Cab
Track, Front76.076.0
Track, Rear73.673.6
Overall Width @ SgRP Front79.579.5
Overall Height80.480.8
Front ground clearance, 4x210.310.3
Front ground clearance, 4x48.38.3
Rear ground clearance7.27.2
Fuel Tank, gal. (L)52 (197) rear52 (197) rear
Fuel Tank, optional22 (83) side22 (83) side
Seating Capacity, F/R3/-3/3
Front Head Room 40.841.0
Front Leg Room41.041.0
Front Shoulder Room67.067.0
Front Hip Room65.065.0
Front Seat Travel7.17.1
Rear Head Room 40.0
Rear Leg Room 36.7
Rear Shoulder Room 66.5
Rear Hip Room 65.3
Rear Knee Clearance 0.7
Front Interior Volume64.865.1
Rear Interior Volume 56.6
Regular Cab - 2WD/4WD

Regular Cab Quad Cab
Cab-Axle60-inch 84-inch 108-inch 120 inch60-inch 84-inch
Wheelbase144.5168.5192.5204.5164.5188.5
Overall Length235.3259.3283.3295.3254.3279.3
Approach Angle, deg.27.828.027.828.127.927.9
Breakover Angle, deg.21.117.815.915.218.218.2
Departure Angle, deg.24.224.124.124.024.224.2
2008 Dodge Ram 4500 and 5500 Chassis Cabs - Safety and Security Features

Following is a list of safety and security features found in the 2008 Dodge Ram 4500 and 5500 Chassis Cabs:

  • Enhanced Accident Response System (EARS) - turn on interior lights and unlock doors after airbags activate
  • Sentry Key Engine Immobilizer Theft Deterrent System - engine key has an embedded transponder
  • Constant Force Retractors (CFR) - front outboard seat belts include a mechanical device designed to distribute the force of a seat belt according to the load of force exerted on it. CFRs are engineered to force-limit the belt system, and gradually release seat belt webbing in a controlled manner during an impact
  • Energy-absorbing Steering Column
  • Four-wheel Anti-lock-brake System (ABS)
  • Knee Bolsters - to further protect occupants during frontal impacts; they restrain and position the occupant properly and enable air bags to work effectively
  • Multi-stage Air Bag System - deploys based on the severity of an impact
  • Seat Belt Pretensioners - During a collision, impact sensors initiate front outboard seat belt pretensioners to immediately remove slack from seat belts, thereby reducing the forward movement of the occupant's head and torso
  • Security Alarm
  • Lower Anchors and Tethers for CHildren (LATCH)
  • Three-point Seat Belts

Main Dodge Ram page | Ram 3500 Chassis Cab | 2011 Dodge Ram Chassis Cabs
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