Dodge started building 4WD pickups after WWII and has since racked up nearly seven decades of providing them to consumers. Many were built under the Dodge name as W-Series pickups and they would later be known as “Ram Tough” and the 4WD pickups would be known as Power Rams. The brand would eventually drop the Dodge moniker and become known simply as Ram trucks. We’ll take a look at some of the popular ½-ton 4WD versions that were developed over the years.
2nd Generation (1965-1971)
By the ’60s, the Dodge pickups had been carrying the “D” designation for 2WD models and the “W” designation for the 4WD models. The ’65 model year saw a new design of the trucks. Wheelbase was 114 inches for the 61⁄2-foot bed and 128 inches with the 8-foot bed. Suspension consisted of front and rear leaf springs, and brakes were originally manual drum-drum configuration. Power assist brakes would become an option for the ’68s. Power steering was also an option in these years.
Dodge started using the LA series engines in place of the previous A-series powerplants. It offered the 225ci Slant I-6 and 318ci V-8 most commonly in the 4WD trucks. Common transmissions included the A230 and A745 three-speed manuals, NP435A closed-spaced ratio, four-speed manual, or the NP435B geometric ratio, four-speed manual. For an automatic, it was the three-speed Loadflite (Torqueflite version for trucks) transmission.
Axle ratios were typically 3.54:1 or 4.10:1. Front axles were Dana 44s, while rear axles were the 30-spline Chrysler 83⁄4-inch units or the 27-spline Chrysler 81⁄4-inch models in some trucks. A rear Anti-Spin differential was often an option.
Earlier trucks through about ’68 models ran the cast-iron, gear-drive NP201 transfer case (1.96:1 low range), with late models getting the cast-iron, gear-drive NP205 transfer case with the same low-range ratio.
3rd Generation (1972-1980)
For the ’72 model, Dodge introduced a new body style with more rounded body lines. The heavier 1⁄2-ton version truck, the W150, was introduced for ’77, while the lighter W100 continued to be offered.
The suspension remained traditional leaf springs front and rear, with recirculating-ball power steering as an option. Brakes were power assisted front disc and rear drum.
Engines included the 225ci I-6, 318ci V-8 and 360ci V-8. The V-8 engines were again the Chrysler LA-series engines.
Common transmissions were the A230 three-speed synchronized manual (mostly behind I-6 engines), NP435 four-speed manual (6.68:1 First gear) or the NP445 close-ratio four-speed manual (4.56:1 synchronized First gear). For an automatic, it was the three-speed Loadflite.
The front straight axles were Dana 44 units, while the rear axles were Chrysler 81⁄2-inch or 83⁄4-inch units. The 31-spline Chrysler 91⁄4-inch axle would also come into use in about 1977. The older Dodge 1⁄2-ton trucks can easily be upgraded to the larger axles from a 3⁄4-ton or 1-ton trucks from this era, and many of the OEM parts are bolt-on compatible.
The NP205 transfer case would serve a few years in this generation and then there was full-time 4WD provided using a cast-iron, chain-drive NP203D transfer case (2.0:1 low range) from ’74 to ’79. Inside, an interaxle differential was used to allow for varying speeds between the front and rear axles on harder surfaces. The transfer case had five settings: High, High Loc, Low, Low Loc, and Neutral. The center differential was locked by placing the transfer case in one of the Loc modes to deliver equal power to both axles.
The NP203D offered drivers the convenience of full-time 4WD but did consume more fuel and wear out the front axle parts at a faster rate than a part-time system. Front axle bearing wear could also be a problem. Mile Marker offered a kit to convert the transfer case to part-time operation and freewheeling hubs could be swapped on the front axles.
In ’80 trucks, Dodge started using the part-time, aluminum case, chain-drive NP208D transfer case (2.61:1 planetary low range).
1st Generation Dodge Ram (1981-1993)
In ’81, the 4WD trucks were deemed Power Rams and Dodge brought back the iconic Ram’s head hood ornament that had last seen use on Dodge trucks in the ’50s. The body was restyled again with updated sheetmetal, grilles, rectangular headlights, and an interior makeover. Models included the standard cab truck, Club Cab (except ’83-’90), and crew cab (through ’85s). Dodge continued to offer the 61⁄2-foot and 8-foot beds. Standard cab, shortbed models had a 115-inch wheelbase, and the line stretched out to a long 165-inch wheelbase for the crew cab longbed model. The ’89 model year saw the last of the W100 trucks.
The I-6 and V-8 engines continued in the line, and the 318ci V-8 got a four-barrel carburetor. The I-6 got electronic spark advance and a hydraulic clutch later for the ’87s. In ’88 vehicles, the 318ci V-8 got throttle-body fuel injection (TBI), and the larger 360ci V-8 got the TBI a year later. The ’92 trucks enjoyed an engine update for the first time in decades to Chrysler’s new Magnum engines. The I-6 engine was replaced with a multi-port fuel-injected 3.9L V-6. Multi-port fuel injection was also introduced in 92 on the Magnum 318 and then on the Magnum 360 in 1993.
The NP435 four-speed manual transmission was still available during much of this time. The three-speed auto served through about the ’89s and was then replaced with the A518 four-speed auto (0.69:1 overdrive).
The NP208D continued to be the transfer case of choice through the ’87s. Starting with the ’85s, Dodge stated its Ram Trac transfer case allowed shifting in and out of 4WD at speeds up to 55 mph thanks to a sliding collar mechanism in the front axle to engage and disengage front drive. We know it as Central Axle Disconnect, or CAD. It operated from a vacuum motor to move the collar mechanism. These systems often proved to be troublesome as they aged and suffered vacuum loss.
Starting in the ’88s, the aluminum-case, chain-drive NP241D transfer case (2.72:1 low range) was used going forward. In the ’89s, rear antilock brakes were added as standard equipment.
2nd Generation Dodge Ram (1994-2001)
A new body style was again introduced for the ’94 model year. It had a big rig look of the dropped fenders and a front grille that lifted up with the hood and set the auto-buying world on its side. It was available originally only in a standard cab configuration and the truck was now known as the Ram 1500, 2500, or 3500.
Dodge would move from front leaf springs to coils with the ’94 model, running a linked front suspension. Leaf packs still suspended the rear of the truck. Front axles continued to be the Dana 44, while the rear axle was most often a Chrysler 9 1⁄4-inch. Axle ratios ranged from 3.54:1 to 4.09:1. Optional four-wheel ABS also became available on this generation Ram truck.
Dodge would continue to offer the 3.9L V-6, 5.2L V-8, and 5.9L V-8 Magnum engines. By the time the ’96s came around, the automatic transmission was electronically controlled. Auto transmissions were typically the A518 (46RH) with 0.69:1 overdrive. The five-speed manual was usually the NV3500 (0.73:1 overdrive) or NV4500.
Transfer cases continued to use a 2.72:1 planetary low range and the Ram 1500 came equipped with the NP231DHD model. Some were manual shift and some were electric shift models.
3rd Generation Dodge Ram (2002-2008)
This new body design took about 3 inches from the bed length and added it to the cab length, leaving the overall length of the truck about the same. Underneath, the truck had a new chassis and suspension for this generation. The Ram 1500 no longer used a straight front axle and now had torsion-bar independent front suspension (IFS) with rack-and-pinion steering. The rear leaf springs remained but were lengthened about 3 inches. Four-wheel disc brakes were introduced in this generation, with a four-wheel ABS option.
Engines in these years were the 3.7L V-6, 4.7L V-8, 5.9L Magnum V-8, and the 5.7L Hemi V-8. Then, for the 2006 model year, a new multi-displacement system was used on the 5.7L Hemi to improve fuel-efficiency. Under light-load or cruise conditions the engine would shut down four of the eight cylinders to conserve fuel.
Transmissions for the third generation 1500 4WD were commonly the four/five-speed 45RFE (four-speed with an extra kick-down Second gear), then later a five-speed automatic transmission (545RFE) was offered to replace the 45RFE behind the V-8 engines. Manual transmission was typically the NV3500, then changing to the six-speed Getrag in 2005. The common transfer case at this point was the NP24xD series where the ‘x’ offered T-case variations (all 2.72:1 low range), with some manual and some electric shift. Axle ratios were usually 3.55:1 or 3.92:1.