Dodge Dakota 1997-2004: more technical details than you can shake a stick at
Dodge Dakota engines
5.2 liter V8 (318)
In 1996, the 5.2-liter engine remained the only V-8 and the most powerful engine in its class. This engine gave Dakota the best acceleration and highest trailer towing capacity in its class. Sequential multi-point fuel injection provided responsive performance. Power and torque ratings increased for 1997 as a result of reductions in intake and exhaust system flow restriction. The 1997 ratings were 230 bhp at 4400 rpm and 300 lb-ft torque at 3200 rpm.
New extended-tip spark plugs having a 0.010 inch (025 mm) larger gap than in 1996 were installed in the 5.2-liter V-8 engine. Combined with a slight change in ignition timing at idle, they improved idle quality in neutral.
A new air induction system reduced air flow restriction and increased power and torque slightly. The system consisted of a bonnet clamped to the throttle body and a molded duct between the air cleaner housing and the bonnet. Engineers used Computational Fluid Dynamics, a graphic model of induction system air flow, to design the system. The model showed flow regimes - laminar, turbulent and stagnant conditions - and estimated restriction. The final configuration was achieved through fine tuning of air cleaner housing volume and inlet duct length
Flexible, accordion-pleated cuffs integrated with the duct clamp over nipples on the bodymounted air cleaner housing and the bonnet. The cuffs provided a tight seal that contributes to low induction noise and keeps dust from bypassing the air cleaner. The accordion pleats accommodated relative motion between engine and air cleaner.
3.9 liter V6 and 2.5 liter AMC four-cylinder engines
A new air induction system, sequential fuel injection, and a larger, free-flowing muffler contributed to the 3.9 L V-6 engine's power. New extended-tip spark plugs having a 0.01 inch ( 0.25 mm) larger gap than in 1996 were installed in the 3.9-liter V-6 engine. Ratings for 1997 remained 175 bhp at 4800 rpm and 225 Ib-ft torque at 3200 rpm as in 1996, though the new air induction system reduced air flow restriction. The induction system had the same configuration as the 5.2-liter V-8 induction system described above.
The 2.5-Liter, OHV, SMPI, four-cylinder was more powerful than its domestic competitors’ four-cylinder engines. Ratings remained 120 bhp at 5200 rpm and 145 lb-ft torque at 3250 rpm, the same as in 1996. The engine air intake system used a "quarter-wave" tuning chamber in the intake duct and a Helmholtz resonator mounted atop the throttle body to reduce induction noise and provide a pleasant sound. The quarter wave tuning chamber dampened unpleasant sounds that have frequencies that are a fractional multiple of the basic induction frequency. The tuning chamber was a closed-end tube paralleling the intake duct that terminated in an elbow leading to a port in the side of the duct. The length, diameter and port location determined its tuning effect. The duct and tuning chamber were molded in one piece. The resonator was a molded plastic housing the volume of which was tuned to damp out air intake pulsations. The top surface of the resonator was ribbed for stiffness. Flexible, accordion-pleated cuffs integrated with the rigid duct and tuning chamber unit seal connections at the body-mounted air cleaner and the engine-mounted resonator as on the 5.2-liter induction system described above.
5.2 liter V8
3.9 liter V6
2.5 liter four-cylinder
Engine accessories and such
The air cleaner housing sat atop the right front inner fender. Inlet to the air cleaner was in the front corner of the engine compartment to minimize the possibility of water and snow ingestion into the air cleaner. The rectangular, pleated paper air filter, which was the same for all engines, had more than twice the area of the previous four-cylinder engine air cleaner and was over 50% larger than that used previously with "V"-type engines.
The pulley ratio of all generators was increased 13% to increase available output throughout the rpm range. The standard 117 ampere generator carried over for 1997. The standard battery with all configurations was rated at 600 cold-cranking amperes. Starters were unchanged for 1997.
The battery tray was molded of corrosion resistant structural plastic. It included mounting provisions for the electrical power distribution center and for a temperature sensor used to assure the appropriate battery charging rate. The battery was protected from high underhood temperatures by a molded thermo-guard cover.
Dodge Dakota pickup truck transmissions
The wide-ratio 44RE four-speed automatic transmission, which replaced the 46RE unit, was used with the 5.2-liter V-8 engine. Its higher numerical ratios for first and second gears provide better launch feel and quicker low-speed passing. They also contributed to easier towing and operation under full load on steep grades The new transmission was also 18 pounds (8.2 kg) lighter, had less inertia, and had less parasitic drag than its predecessor to help improve fuel economy. Ratios were:
Durability was increased by preventing overdrive operation at low temperatures to assure ample fluid circulation; when ambient temperature was below -5˚ F (-20°C) or transmission fluid is below 30˚F (-1°C), overdrive operation was inhibited. TEC continuously monitored transmission temperature and allowed overdrive operation when the appropriate temperature was reached. TEC continued to use high temperature readings at the transmission temperature sensor to prevent overdrive operation for increased cooling; it also turned on the TRANS TEMP light in the instrument cluster, which was included with all automatic transmission applications for 1997.
Transmission control logic gave both Dakota automatic transmissions the ability to avoid "hunting" - a series of upshiftdownshift cycles accompanied by noisy engine "flare" - when ascending a grade or during acceleration with a heavy load. Upshifts are postponed until the engine has sufficient power to maintain speed in the higher gear. This affected both 2-3 and 3-4 shifts. Grade hunting prevention worked with automatic speed control as well as normal driver control.
Refinements in the NV3500 manual transmission, which was used only with the V-8 engine, improved shift quality and reduced gear noise. To make engagement of First and Second gears easier, the 1-2 synchronizer had a dual-cone design that reduced shift effort by up to 40%. The force reduction resulted from addition of a second friction load path.
Quieter operation resulted from a change to finer pitch gears for third and fifth speeds. Finer pitch placed more teeth in mesh at the same time, distributing the loads to reduce noise.
A high-efficiency clutch hydraulic system provided smoother pedal operation, using higher internal pressure for greater precision, reduced hysteresis, the difference in operating force between release and engagement - and started engagement closer to the floor than in 1996 as requested by customers.
A new front axle assembly on 4WD models used an aluminum housing and tubes to reduce weight 29 pounds (13 kg) compared to the former steel housing. It remained the same in concept as its predecessor - a non-load-bearing assembly that resembled a narrow conventional rear axle without brakes, but had larger gears to increase durability. It was narrower than its predecessor to allow the use of longer drive shafts for more wheel travel within the limits of constant-velocity joint travel.
New front hubs on 4WD models used a sealed double-row tapered roller bearing assembly. Only three bolts were required to attach the hubs to the knuckles, compared to four on the previous design. The bolts passed through the knuckles from the inboard side and threaded into the hub units, eliminating a threading operation on the knuckles. With anti-lock brakes, the wheel speed sensors were incorporated into the hub units.
Dodge Dakota frames
Dakota frames were redesigned to increase stiffness, strength, durability and dimensional accuracy. Frame stiffness is a multiple of the stiffness of the springs, shock absorbers and rubber mounts. A relatively low multiple (low stiffness) allows the frame to flex - twist or bend resulting in noisy operation and poor ride and handling. A relatively high multiple allows the tires, springs, shock absorbers and rubber mounts to do the work of responding to external inputs with minimal frame flex. Stiffness is balanced against strength, durability and weight requirements. Strength and durability are particularly important for a truck, which must operate under high loads and hard usage. To provide strength and durability with reasonable weight requires a measure of flexibility to prevent frame breakage. The 1997 Dakota achieved a balance that allowed the springs, shock absorbers and rubber mounts to be effectively tuned for quietness, a smooth ride and responsive handling characteristics.
On 2WD models, frame torsional stiffness was increased 50% overall and over 150% in the front suspension area compared to 1996. Three-section side rail construction, first used on the Ram pickup, is common to both 2WD and 4WD frames. Both frames provided tire clearance to assure a tight turning circle. The front section, from front cross member to cab, had nested C-section rails as in the past. However, the inner rail thickness was increased for added durability. Center section rails had a modified C-section with turned-in lips for increased stiffness. Rear rails had an open C-section. Side rails and cross members were joined by welding as in 1996. Center and rear sections overlap at the rear spring front eye mounting bracket, a point of high stress. This allowed the use of lighter weight material in both sections while maintaining requisite durability. To further strengthen this area, the front eye bracket was riveted through both sections. Wheel base differences were accommodated in both center and rear sections.
A new box section front cross member increased torsional stiffness, provided support for the stabilizer bar, and aided dimensional control. A new structural transmission cross member, which attached to the webs of the frame side rails with four bolts per side, contributed to the overall stiffness increase.
The 4WD frame was completely retooled with enhancements for durability, dimensional control, and stiffness. Improvements included stiffer torsion bar and transmission cross members and deletion of the crossmember for the stabilizer bar, which was relocated from the back to the front of the suspension making a dedicated cross member unnecessary. A stronger optional 4WD transfer case skid plate resulted from increased material thickness and a new mounting arrangement
A multi-purpose rear cross member used on both 2WD and 4WD frames, replacing two cross members and a diagonal brace, contributed to frame torsional stiffness and reduced the possibility of parallelogramming - longitudinal distortion between the side rails. It was riveted to both top and bottom flanges of the frame rails for maximum stiffness benefit. It also provided mounting points for the left shock absorber and the spare tire winch to minimize weight.
Mounting brackets on both frames for suspension, cab and box were stiffer than those on prior frames. The localized stiffening assured that the overall frame stiffness improvement was used effectively. The front stabilizer bar was mounted to a frame cross member to reduce deflection. Separate cargo box and cab mounting brackets replaced a common mounting bracket system. The box mounting brackets were stiffer than in 1996. Cab mounting brackets were both stiffer and farther outboard than before, allowing the cab to contribute more to overall vehicle stiffness.
Proving grounds durability testing demonstrated a frame durability increase of over 50% from 1996, resulting in structure that would stay tight throughout the life of the truck. Changes to increase durability included use of 35,000 psi yield strength steel, an increase of up to 40% over the former material, metal thickness optimization, changes in welding processes, and redesign of engine mounting brackets, cab brackets, the torsion bar cross member, lower control arm brackets and the front suspension cross member. Finite Element Analysis stress models helped determine where and how to make the improvements.
The frame was electro-coat painted to significantly increase corrosion protection and improve both short- and long-term appearance. This immersion paint process assured complete coverage and a uniform coating. The finish was impervious to vehicle fluids and had a durable, low-gloss finish that was smooth and hard to the touch. This give Dakota a significant advantage over its domestic competitors that still used the traditional wax-dip coating, which driped in hot weather, rubbed off, was less pleasing in appearance, and offered less corrosion protection.
As the mounting point for the bumpers, cab, box, suspension, steering and powertrain, the frame was a major contributor to dimensional control throughout the truck. New manufacturing processes and dimensional control techniques provided up to 50% improvement in attachment point accuracy for 1997. This was aided by a reduction in the number of pieces that had to be accurately attached to the frame assembly. For highest accuracy, all frame dimensions were measured from a single set of principal locating points (PLPs). The processes used to achieve the desired level of accuracy were refined through multiple iterations of Variation Simulation Analysis (VSA). VSA uses production process parameters to predict the degree of accuracy produced by a set of processes. The frame was manufactured in three stages:
1. the basic frame was welded using the PLPs
2. all mounting brackets were positioned relative to the PLPs and welded in a single fixture
3. all critical suspension, steering and body mounting holes were pierced in the brackets relative to the PLPs simultaneously in another fixture
Body mounting brackets were welded to the webs of the frame after the rails and cross members were welded together to permit the fixture to control vertical mounting locations. Lateral and longitudinal mounting locations were controlled by the piercing fixture. Steering toe control for consistent handling was a major benefit of improved dimensional control since the steering gear to lower control arm relationship, which governed this condition, was established by the frame mounting points for these components.
Trailer Hitch Platform
A frame-mounted Class IV trailer hitch platform continued as a factory option on Dakota, except short wheelbase models or those with four-cylinder engines. It provided properly equipped Dakota models with towing capacity up to 6800 pounds (3084 kg). The platform accepted standard, removable load-equalizing draw bar units. For an uncluttered appearance, the platform lateral tube was concealed behind the standard rear bumper, only the draw bar "box" was visible.
Dakota was expected to have the best steering feel, best ride, and most precise handling of any pickup truck available in the USA. Customers were expected to perceive Dakota's handling characteristics as those of a touring sedan, with outstanding, car-like handling capabilities even as it retained truck functional attributes. Dynamics development began with basic designs and concluded with fine tuning of the finished truck. Basic areas affected included:
- Total vehicle damping - leading-edge non-linear damping characteristics in suspension, cab and powertrain mounts along with shock absorber calibration - provided a solid road feel with low harshness even on bumpy roads.
- Firm, crisp and precise steering with excellent returnability as the result of a systematic analysis and refinement of the steering system.
- Directional stability (straight line tracking) and steering feel resulted from front suspension geometry that provided a small scrub radius and appropriate caster, camber and toe patterns. (Scrub radius is the lateral offset between the ground-level intersection of the steering axis and a plane through the centerline of the tire) Benefits of a small scrub radius include directional stability, steering feel and enhanced driver confidence.
On 2WD models, the scrub radius was reduced from 1996 by over 1.75 inches (45 mm) with standard tires and 1.3 inches (33 mm) with the Tire and Handling package to the lower control arms. New rubber stabilizer bar pivot bushings were larger but firmer than their predecessors due to solid, slit-free construction. Low-friction plastic liners reduced noise and increased bushing durability.
Hub unit front spindle bearing assemblies were more compact than conventional inner and outer tapered roller bearings, contributing to reduced scrub radius. These double-row bearing assemblies were pre-lubricated, pre-adjusted and sealed for long life. They pressed into the hubs and sliped over hardened steel spindle inserts, which were shrink fitted in the knuckles and required no machining. Rather than being machined, the spindle's net dimensions were formed by a precision cold heading process for the main portion and a rolling process for the threads. Net forming was enabled by the elimination of the keyway and cotter pin hole used in the former bearing adjustment process. Hub installation on the truck at assembly required no adjustment; it used a single high-torque nut.
Cast iron steering knuckles included integral steering arms and brake anchors. Steering arms were located to reduce toe change across the full range of suspension travel over 65% - from 3.42˚ to 1.19˚ - compared to the prior system. Toe change was also balanced about the curb load position. The combination of these changes contributed to a uniform steering feel and precise handling.
Springs continued to be computer selected to provide proper support regardless of load, but all rates were lower. To maintain ride quality with heavier loads, all springs were designed to provide the same ride frequency. This also facilitated shock absorber tuning to provide appropriate control under all load conditions.
Four-Wheel Drive Front Suspension System
A redesign of the 4WD torsion-bar independent front suspension accommodated 31 x 10.5R15 tires on 15 x 8-inch wheels while cutting the turning circle, and improving ride, cornering and steering performance. 4WD durability was maintained by raising the upper control arm 075 in. (19 mm), camber change over the full range of suspension travel was reduced over 40% compared to 1996. Camber variation from the nominal setting was also balanced between jounce and rebound conditions relative to curb height, where the prior design produced relatively large amounts of negative camber in rebound. Steering arms were relocated on the knuckles to balance toe change during jounce and rebound about the curb load position The effects of these changes was to significantly reduce tire wear by keeping the tires more upright and straighter than before.
Scrub radius was reduced by moving the lower ball joint outboard 0.135 in. (35 mm) and shortening the upper control arm 0.2 in. (5 mm). The effect of these subtle changes was magnified by the geometry, reducing scrub radius 0.6 inches (15 mm) with standard tires and 0.1 in. (24 mm) with the optional 31-inch tires, which were offset outboard by 0.5 in. (13 mm) each for clearance. A new low-friction, compression-type lower ball joint design reduced steering friction for enhanced precision feel and improved returnability.
Front stabilizer bar diameter was increased from 0.94 to 1.10 in. (24 to 28 mm), providing 60% more stiffness than the prior model for increased cornering stability, reduced body lean, and improved steering response. Steering response was enhanced because the truck reached a stable cornering stance and turned in sooner than one with a more flexible bar. New rubber stabilizer bar pivot bushings were larger but firmer than their predecessors due to solid, slitfree construction. Low-friction plastic bushing liners reduced noise and increased bushing durability. To reduce turning circle, the stabilizer bar was mounted forward of the lower control arms. This location was also farther above the ground than the previous mounting for improved all-terrain capability. Stabilizer bar connection to the suspension remained linkless - each end of the bar pilots in a rubber bushing attached to a lower control arm. A new rubber compound increased bushing durability.
Rear Suspension System
Rear suspension was unchanged in concept from 1996 - leaf springs with a solid axle - but refined to improve ride and handling and to reduce harshness. Rear track was increased 2 inches (51 mm) to 61.5 inches (1562 mm) with standard and higher load capacity tires by widening the axle. With the Tire and Handling packages, additional wheel offset increased track by an inch (25 mm). In addition to accommodating larger tires, the wider track reduced body lean. A tight toe specification for the rear axle housing contributed to handling precision by assuring that rear wheels maintained a toed-in attitude.
Single-stage springs were used on standard-duty 2WD models to improve ride quality. They were firmer initially than the former two-stage springs, but were free of the harshness that occurs when loading or sharp bumps bring the secondary leaves into action. The higher basic rate also kept the body attitude more consistent from empty to loaded condition than do two-stage springs. For ride comfort, the shock absorbers were specially tuned for the single stage springs.
To reduce harshness, front eye bushings were enlarged from 1 to 15 inches (25 to 38 mm) in diameter, doubling their volume. Staggered shock absorber mounting - one ahead and one behind the axle housing - helped control "power hop." On 2WD models, the bottom of the spring front hanger bracket was trimmed approximately 05 inch (13 mm) to increase the ramp breakover angle.
A rear stabilizer bar was included with the optional Tire and Handling package which was available on both 2WD and 4WD models. The bar pivoted on the axle housing and was connected to the frame through low-friction links.
Shared Suspension Components Jounce Bumpers
Micro-cellular urethane jounce bumpers were used in the 4WD front suspension for the first time in 1997 and continue in use on the 2WD front suspension. Unique jounce bumper designs for each configuration fit the environment and suspension characteristics. They contribute to high quality ride and handling characteristics by providing a rising-rate that reduces harshness and the impact of "bottoming out." Each bumper was encased in a steel cup that acts as the full-travel stop and helped create the rising rate effect. Urethane had the added benefit of a nearly constant rate regardless of temperature to help maintain ride quality in all seasons and greater durability than conventional rubber bumper material.
Shock absorbers used a combination of deflected disc and helical spring valves for maximum flexibility in damper tuning to control ride motions. Deflection characteristics of the valves permited oil passage area to vary relative to shock absorbers velocity. Generally, the faster the motion of the suspension in traversing a bump, the larger the passage area, limiting the damping force. When traversing sharp bumps, which produces high shock absorber velocities, the controlled damping force reduces harshness. Conversely, low shock absorber velocities associated with road undulations or cornering gives firm control for stability and driver confidence. Deflected disc valves also had low hysteresis, which helped to minimize harshness, and provided smooth transitions between jounce and rebound. Final shock absorber valve configuration was the result of painstaking comparison testing among numerous possible combinations.
With 4WD, shock absorbers had 1.38 inch diameter pistons - 36% more area than in 1996 for increased durability and better low-speed ride control. These shock absorbers were also used on some 2WD models as required for durability and ride control The remaining 2WD applications used new 1.18-inch shocks that had the same housing outer diameter as the larger units, provided added fluid capacity for enhanced ride control on bumpy roads through lower fluid temperatures.
All Dakota shock absorbers had conventional twin tube construction and a low-pressure gas charge to prevent cavitation (formation of air pockets that can adversely affect ride quality) during rough road operation. Larger upper shock mounting grommets also increased durability.
Compression-type ball lower ball joints were used in both 2WD and 4WD front suspensions. A compression ball joint is smaller in diameter than a tension joint of equal strength because the compression side of the joint, which has a larger area than the tension side, is used to support the vehicle's weight and jounce loads. A hard, durable plastic ball socket liner contributed to responsive steering by reducing turning loads. Similar reductions in ride friction were compensated by shock absorber tuning. Both 2WD and 4WD upper ball joints as well as the 2WD lowers were permanently lubricated and maintenance free. Improved sealing assured durability equal to or greater than that provided by ball joints that require periodic lubrication
Suspension System Corrosion Protection
All 2WD front suspension components were painted to increase corrosion resistance and improve appearance. The black finish was applied by an electrocoat process that assured complete coverage, evenly applied.
Electrocoat painting of 4WD steering knuckles, the stabilizer bar and its mounts and the torsion bars to improve appearance and reduce corrosion was new for 1997. Use of the same process to paint the springs and control arms continues.
Rear shackles and spring clip plates were also painted using an electrocoat process. Springs received a proprietary, two-part treatment consisting of a corrosion-resistant zinc-rich primer followed by an appearance top coat.
Most threaded fasteners in the suspension system were finished with a proprietary coating that had an appealing bright appearance and was 5 times more resistant to corrosion than fastener finishes used previously.
Steering systems on both 2WD and 4WD models provided faster response, better road feel, and a tighter turning circle than their predecessors. Vehicle response to steering inputs was more proportional than before, which gave a feeling of a direct connection between driver and road that helped make the truck fun to drive.
On 2WD models, the overall on-center steering ratio was 14.8:1 - 12% faster than in 1996. The power rack and pinion system combined an ultraquick-response valve that required costly precision machining with a stiff torsion bar actuator. For increased precision, a new rack bearing reduced internal friction below 1996 levels. Rubber mounts for the steering gear were firmer to reduce steering deflection for enhanced precision. Though smaller, these mounts were tuned to maintain the same degree of isolation from noise and vibration at the steering wheel as their predecessors.
The new rack and pinion steering gear on 2WD models had a l-inch (28 mm) diameter rack. This 12% size increase provided the increased travel required to increase turning angles and increased load capacity to steer larger optional tires.
The overall on-center ratio of the power recirculating-ball gear used on 4WD models was reduced 6%, to 1543: 1. The valve and torsion bar on this gear were refined for improved responsiveness in a manner similar to that on 2WD models. Precision feel was aided by reducing internal friction through improved manufacturing processes and new seals. In addition, the linkage was completely redesigned to increase its stiffness and reduce friction for precision and responsiveness. In-line spherical joints connected the center link to the tie rods, reducing deflection under load compared to their offset antecedents. This construction is also more durable than its predecessor. Low-friction plastic liners in these joints helped minimize friction The tie rods thread directly into the tie-rod ends and are held in adjustment by jam nuts This made toe adjustment more precise and easier than with the former clamped-sleeve arrangement. A conical joint transfered steering motion from the pitman arm of the steering gear to the center link. This joint is more precise than the spherical joint used previously in this location The spherical joint, which compensated for minor angular variations in the linkage, was moved to the idler arm where it does not affect precision.
A new heavy-duty steering gear, the same size as that used on Ram pickups, provided added strength for the added weight of V-8-powered 4WD club cabs and 4WD models with the optional Snow Plow package.
Tighter Turning Circles
The 2WD Dakota club cab had a tighter turning circle than any competitive long wheelbase pickup. For 1997, the turning circle was reduced on 2WD models by up to 4.7 feet (14 m) and on 4WD models by up to 3.7 feet (1.1 m). Turning circles were reduced by a complete redesign of both 2WD and 4WD front suspension systems to allow larger steering angles as described elsewhere. The reductions in turning circle for all models are summarized in the following chart.
Sliding caliper front disc brakes and duo-servo drum rear brakes were standard on all models. Single-piston front brake calipers had 2.6-inch (66-mm) pistons as in 1996. Rotors remained at 11.3 x 0.9 inches (287 x 23 mm). Standard rear brakes had 9.0 x 2.5-inch (229 x 64 mm) drums as in 1996. With payloads of 2000 pounds or more, 10 x 2.5-inch (254 x 64 mm) rear brakes were included as in 1996.
An integrated booster and master cylinder required minimal pedal travel to actuate the brakes, enhancing driver confidence. The booster diameter remained at 10.6 inches (270 mm), as in 1996, but the master cylinder bore was enlarged slightly to 1 inch (25 mm) to reduce pedal travel for quicker response.
The brake system includeed the following additional features:
- All systems were self-adjusting.
- Lining materials contained no asbestos.
- front disc brake calipers, rotor hubs and rear brake drums had a black anti-corrosion coating to improve durability and appearance.
- Brake line life was increased by adding an aluminum-rich coating for corrosion protection.
- Steering knuckles on 2WD models included new integral brake caliper anchors for simplicity and low weight (integral caliper anchors carried over on 4WD models)
Full-coverage shields protected the front discs on 2WD models from dust, dirt and road splash to reduce lining wear during all-terrain driving. Shields also covered the front half of the discs on 4WD models. The rear portion was effectively shielded by the caliper and the steering knuckle.
Four-Wheel Anti-Lock Brakes
State-of-the-art four-wheel anti-lock brakes were optional on all Dakota models. The major system improvement for 1997 was the addition of powered ABS action to the rear brakes. This resulted in subtle improvements in stopping distance and control for the driver when braking on rough roads, on roads with side-to-side variations in surface friction, and during steering maneuvers. Powered operation meant that, if hydraulic pressure was released to prevent lockup, the hydraulic unit would pump the fluid back into the rear brake system to maintain pedal height. The previous Dakota four-wheel anti-lock system had powered operation of the front brakes but the rear brake system was the same as the standard RWAL (Rear Wheel Anti-Lock) system, which allowed the pedal to drop during anti-lock action. Pedal feedback, which included some pulsation to indicate anti-lock action, is the same as with the 1996 system.
Reduced scrub radius front suspension steering geometry also contributed to improved antilock performance by allowing the system to provide more aggressive initial application than its predecessor while maintaining directional control and steering capability.
Front wheel speed sensors on 2WD models remained unchanged in concept from 1996 but were redesigned for the new steering knuckle and brake environment. On 4WD models, front wheel sensors integral with the hub bearings were simpler and more reliable than the previous external sensors. The single rear axle sensor, which was used with both RWAL and four-wheel systems, continued to use the ring gear as its trigger.
The anti-lock brake system was operated by a new electronic control module, which had been integrated with the hydraulic unit for 1997. This integration simplified the wiring and enhanceds system reliability by providing internal electrical connections that eliminated 15 external electrical circuits required previously. This integration also reduced the weight of the system by approximately 2.5 pounds ( 1.1 kg) relative to the 1996 system. ABS system malfunctions were communicated to the instrument cluster warning indicator over the multiplex data network, eliminating the need for a separate circuit.
Rear-Wheel Anti-Lock Brakes
Rear-wheel anti-lock brakes continued as standard equipment on Dakota. A single sensor on the differential housing provided the input signal to control the rear drum brakes. Hydraulic pressure to both rear wheels was reduced if wheel lock up was sensed. A brake control module monitored operation of the system and included diagnostic routines to aid in correcting malfunctions.
A new parking brake mechanism in the cab operated more quietly and smoothly than its predecessor. The pedal for applying the brake was mounted on the left cowl side, as in the past, but produced none of the characteristic ratchet sound of its predecessor during application. Instead of a ratchet, the new mechanism used a square-edged spring that wraped around a drum operated by the brake pedal to keep the brake engaged. When the brake was applied, the drum slid smoothly inside the spring. When foot pressure on the pedal was released, the spring grips the drum and prevented it from returning to its released position. The release lever was integrated with the lower edge of the instrument panel just above the pedal. Release effort was reduced more than 50% compared to 1996 and operation was smooth and quiet. The previous mechanism released suddenly and return of the pedal was sometimes accompanied by a load noise when the pedal reached the full-release position. The 1997 mechanism released gradually, by pressing against the end of the square-edged spring to reduce its grip on the drum, and the pedal rotated back to its released position smoothly.
Fuel Supply System
New standard and optional fuel tanks were made of high-density polyethylene. Standard fuel tank capacity remained 15 gallons. A 22-gallon tank was optional as in the past. Tanks were mounted inboard of the frame rails.
A door in the left side of the pickup box concealed the fuel filler cap. The door pivoted on a spring loaded hinge that held the door open for refueling. Inside the door was a convenient cap-retainer bracket.
A one-piece filler tube reduced complexity and the potential for fuel vapor evaporation compared to its predecessor. The flexible fluoropolymer tube assembly snaped onto a nipple on the tank using a unique quick-connect coupling. This connection was less permeable to fuel vapor than the former multi-piece assembly, which had a steel tube and an adapter hose. Assembly was easier than before because the previous adapter hoses required clamps that were manually tightened. Fuel line life was increased by adding an aluminum-rich coating for corrosion protection.
An all-new exhaust system that included a larger muffler and shorter pipes reduced system backpressure compared to the 1996 system. Muffler volume was increased 13% compared to prior models for a quieter tone and lower back pressure. Redesigned exhaust pipe and tailpipe routing permited use of full diameter pipes. Formerly, pipes were locally restricted to clear various components. The new routing brought the tailpipe outlet 5 inches (127 mm) farther forward than before and kept most of the pipe concealed by the body for a neater appearance. Hangars were located at vibration nodes to minimize noise transmission and increase system durability. Node locations were determined by vibration mapping. The muffler, catalytic converter housing and all pipes remained stainless steel.
Cross-flow aluminum radiators with plastic end tanks provided increased cooling capacity for all engines. Mechanically attached plastic end tanks handled thermal expansion cycles better than the conventional soldered copper-brass construction for longer life. Aluminum radiators weigh less than copper-brass radiators of comparable cooling capacity. For example with V-8 engine the standard aluminum radiator weighs almost 11 pounds (5 kg) less than its copperbrass predecessor. With appropriate coolant formulation, aluminum has double the corrosion resistance of copper-brass. All radiators have the same face area but different core thickness to meet varying cooling requirements. Cross-flow construction was used because its low, wide configuration consistent 'Nith the low hood line of the new Dakota pickup.
A state-of-the art mounting system assured long radiator life. Rubber mounts isolated the radiator from engine and chassis vibrations.
Fan noise with V-6 and V-8 engines was significantly reduced from 1996 levels. All radiators had a face area that was 7% larger than that of their predecessors, increasing the area through which cooling air passed. This reduced fan noise by reducing the amount of work the fan had to do. Fan size was tailored to each engine on the new Dakota, allowing the V-6 fan to be 0.5 inch (12 mm) smaller than its predecessor. This not only reduced noise, it also reduced the fan's power requirement to increase fuel economy. Fan drives were fine tuned to reduce fan speed for lower noise where appropriate. With the 2.5-liter engine, the fan was driven by an electric motor as in 1996.
A more robust thermostat used with all engines provided longer, more reliable life. Subtle design and manufacturing process changes made it more durable and also provided closer control of temperatures than the prior design.
The coolant recovery reservoir was mounted forward of the radiator closure panel, with its neck extending into the engine compartment through an opening in the closure panel for easy access. The bottle was molded in black plastic to match the black paint on the front of the closure panel for a consistent appearance, but the cap was yellow with black nomenclature for easy identification.
The maximum cooling package, which was required for towing heavy trailers and plowing snow, included a thicker radiator core, larger fan, higher capacity fan drive, and, with automatic transmission, an auxiliary transmission cooler mounted ahead of the radiator. This package helped Dakota maintain its best-in-class (GCWR) gross combined weight rating of 10,500 pounds.
Exterior body panels were designed to resist denting in parking lot and cargo loading situations. Panel surface design, appropriate material thickness, reinforcements and metallurgy, such as the high strength steel door outer panels, were used as required to meet dent resistance requirements.
All body opening gaps were 0.18 in. (4.5 mm) a reduction of 0.02-006 in. (0.5-15 mm) from previous practice. A small gap between box and cab enhanced the appearance of continuity. The box sides extend forward slightly, reducing the visual gap to less than .075 in. (19 mm), approximately 0.4 in. (10 mm) less than the prior model.
The hood with attached grille opened on counterbalanced hinges that reduced opening effort by 50% compared to the 1996 Dakota. The hinge design provided a minimum of 6 feet (1.95 m) of clearance beneath the grille with the hood fully open. Full-coverage molded plastic front wheelhouse liners, which were unique to Dakota in its class, protected the front end sheet metal from stone damage and road splash. They also helped block the sound of road noise and road splash from reaching the cab.
The radiator closure included hydro-formed upper and lower cross bars that contributed to structural stiffness, reduced weight, simplified assembly, and facilitated engine removal for service. The cross bar tubes, which were formed to the desired shape in an external die by high pressure water, were designed using the DFMA (Design for Manufacturing and Assembly) process to provide the functions of welded assemblies of several parts. The upper cross bar was bolted in place to facilitate engine removal for service, if needed.
Laser-welded sheet metal blanks for the front fender inner panels provided added stiffness, reduced weight and increased dimensional accuracy compared to a conventional welded assembly. The laser smoothly and precisely butt-welds two pieces of sheet metal having significantly different thicknesses. Added thickness provided needed local strength and stiffness more efficiently than an attached reinforcement.
A computer-designed roof structure had visibly smaller pillars than prior models yet had increased strength to meet the newly applicable roof safety standard. A snap-in molding covered the roof-to-body-side-aperture panel joint on both regular and club cabs for a neat appearance. Center seat passengers in 2WD models with automatic transmission had increased leg room compared to the 1996 Dakota because the floor pan tunnel was 2 inches (50 mm) lower. The tunnel was also narrower, increasing foot room on the driver's side. The tunnel was lowered because the drive line combination required less room than the others.
For better appearance, improved durability, improved passenger comfort and to minimize sunlight damage to interior materials, new deep tint glass quarter and rear windows were included on all club cabs. The new glass reduced the transmission of infrared energy 15% and ultraviolet energy by 2-4% compared to conventional tinted glass. For durability, the tinting agent was molded into the glass, rather than applied to the surface. This new glass also provided a better appearance than previous dark-tint glass because it had a dark color rather than a mirror-like finish. The absence of a mirror coating also improved outward visibility at night. Conventional tinted glass was standard in all door windows and the windshield on all models. The windshield included a customary deeply tinted upper band. On regular cabs, the rear window also had a conventional tint.
Box and Tailgate
The box interior dimensions remained essentially unchanged, maintaining best-in-class capacity for the eight footer. New were wide-spaced front cargo tie-down bars recessed in the floor and concealed by snap-in rubber covers. The bars attached to the structural front box support rail for high strength. Also new rear cargo tie-down loops attached to the base of each tailgate pillar.
The carryover one-piece box floor was made of dent-resistant, high strength steel. The box outer panels were devoid of stake pockets for a neat appearance. Carryover box inner walls retained indentations to support lumber, forming an upper load floor that will carry 4 x 8-foot sheets of plywood or other similar materials with the tailgate closed in the eight-foot configuration. An expandable, structural adhesive bonded the box inner and outer panels, providing superior dent resistance to the upper rail of the box opening.
The tailgate was stamped in one piece. It pivoted on plastic bushings for smooth operation. The pivots stabilized the tailgate to minimize shuffle and the potential for BSRs. A wide, lowprofile release handle had the same design as the door handle. It combined with a recessed escutcheon to assure clearance for a large gloved hand. Low-friction pivots gave it the same feel and easy action as the door handles. The handle and escutcheon were molded in black, glass-reinforced nylon, which had a grained finish designed to resist wax buildup. Tailgate latches and support cables remained unchanged from 1996.
Corrosion protection was the same as in 1996. Every exterior body panel was galvanized or galvannealed to protect against corrosion. Cabs and boxes were thoroughly cleaned and treated with a phosphate coating by immersion. Primer application used the same electro coat (E-coat) process as other Chrysler Corporation vehicles for a uniform coating of all surfaces, including cavities and crevices.
To deter paint chipping, a urethane coating was sprayed on the lower third of the box and cab as in 1996. In January 1997, this coating was replaced by a specially formulated epoxy polyester powder applied to all exterior body surfaces This provided an added measure of chip resistance and also reduced the potential for paint de-lamination due to ultra-violet radiation. This powdered material significantly reduced paint chipping and resisted ultra-violet radiation that can cause paint to de-laminate. Powder anti-chip primer was applied between primer and finish coats. Because it was powdered, its application produces no VOC (volatile organic compound) emissions.
Doors were assembled from full-stamped inner and outer panels adhesive bonded and hemmed together. Doors overlaped the sills, which eliminated a visible sill gap and helping to keep road splash off the inner sills. Outer panels were made of high-strength steel to resist denting. Stamped, one-piece, high-strength, low-alloy side-guard door beams also reinforced the door latch attachment. Door inner panels were stamped from dual-thickness laser-welded sheet metal. The forward portion of the panel, to which the hinges were bolted, was more than twice as thick as the remainder of the panel. This contributed to hinge mounting stability and a solid door closing sound. The inner panel was stronger yet lighter than a single-thickness panel with a welded reinforcement. One-piece aperture panels in the body sides facing the doors contributed to consistency of door fit. Lock pillars on the cab were boxed below the belt line to enhance striker mounting stability. These multi-purpose assemblies also supported the shoulder belt turning loops.
Door and pillar structure was designed to withstand slamming forces without unnecessary weight by using new dynamic finite element analysis (FEA) techniques. Dynamic FEA considers impact velocity, part interactions, and the effects of non-structural parts in computing stress distribution within the structure. It was instrumental in designing the laser-welded door inner panel and in assuring appropriate strength and dimensional stability.
Wide, low-profile outside door handles combined with recessed escutcheons to assure clearance for large gloved hands. The handle return spring was attached opposite the latch lever, balancing loads to help make operation easy. Handles and escutcheons were molded in black, glass-reinforced nylon that had a grained finish designed to resist wax buildup.
Inside door handles were readily accessible at the forward end of the door armrests. They curved inboard for ample finger clearance and pivoted on vertical axes for easy operation. Each handle nested in a trim bezel both of which were assembled to the trim panel, rather than the door inner panel to provide accurate alignment and eliminate a visible fastener. The handle and bezel were black with all interiors. Large, rectangular lock buttons, which rode in pockets molded into the trim panels at the belt line, were easy to grip.
New door latches provided smooth, quiet operation and low effort in release and closing accompanied by high strength. Latch opening and closing make a pleasant, solid sound. Plastic and plastic-encapsulated steel components assured quiet operation and freedom from "chucking" noises during rough-road operation. Solid steel components were used only where required to assure strength and durability. A loop striker on the body offered a "friendly" surface that was unlikely to snag one's clothing. With optional power locks, the lock motors were integral with the latches. This helped minimize manual locking and unlocking effort because the key did not turn the locking motor.
For ease of entry and exit, even in tight parking spaces, a sturdy spring-loaded cam and roller door check mechanism held the doors open at either of two positions. To reduce closing effort, the cam profile caused the check spring force to aid closing. The mechanism was combined with the upper hinge to minimize both weight and cost. The spring that provided the holding force was coated low-friction polymer to reduce noise. The hinge pivot bushings had the same coating to minimize friction and eliminate noise throughout the life of the truck.
Mirrors and lighting
Dual 5 x 7 -inch outside mirrors were standard on all models. They were 45% larger than the previous standard Dakota mirrors. For stability, the mirrors were attached to the reinforced pillar area of the door at the lower front corner of the window opening, rather than to the door outer panel. Mirror housing and arm shape minimized wind noise. The housings and arms were molded of impact and ultraviolet light-resistant black plastic for long life with good appearance. Their grained finish resisted wax and dirt buildup.
Optional 6 x 9-inch power mirrors were the largest optional mirrors available in the class. Like the standard mirrors, larger area and outboard mounting gave them a field of view unsurpassed by any truck in the class - 25% bigger than that provided by domestic competitors. Hinged mounting arms folded forward or back to resist damage. The normal position had a detent to permit easy re-establishment of normal mirror position after folding.
A conventional day-night inside rearview mirror was standard.
Front lamp units were combined in a module for accurate alignment, appearance and ease of assembly. Each module included an aero-style headlight, an amber combination lamp, and a clear faux lamp, all mounted on a carrier bracket. A molded rubber flap attached to the lamp module filled the gaps to the grille and hood for appearance.
Halogen headlights, with new high-efficiency dual-filament bulbs, provided outstanding performance. The new bulbs produced more light per watt than the previous Dakota bulbs. The headlight lenses were made of polycarbonate plastic, which combined high impact resistance with the crystalline appearance of glass. A conventional parabolic reflector and lens optics directed the light output down the road.
The combination lamp included parking lamp, turn signal, and side marker functions. Two, dual-filament bulbs provided park and turn signal operation in each lamp; each side marker had a single bulb. The combination lamp and faux lamp housings were welded together. They were attached to the carrier by three concealed tabs and a single unobtrusive screw.
New taillights combined stop lamp, turn signal, back-up lamp, and side marker lamp functions in a single housing. The housing wraped around the corner of the box to provide required side illumination. The red lens included a reflector section and a clear insert for the back-up lamp function. For neat appearance, there were no visible screws. New dimensional control procedures assured a close and accurate fit in the body opening.
Optional fog lamps had round housings and stone chip-resistant plastic lenses. Halogen bulbs consumed 30% less power than in 1996 but provided an improved light pattern compared to their predecessors because these round lamps distributed light more efficiently. These lamps functioned as fog lamps, not driving lamps, having a low wide beam that illuminated the area immediately ahead of the truck. As in 1996, they could be operated with the parking lamps to realize their capability or as a supplement to the headlights.
A semi-recessed windshield wiper system was integrated with the new hood. The wipers operated at two speeds with variable delay intermittent operation standard. The motor, linkage, and wiper arms were attached to a tubular frame that was mounted in the cowl plenum chamber through four 1.38-inch (35 mm) rubber isolators to minimize noise transmission to the cab. Quietness was enhanced by placing the cycling relay that provided intermittent operation in the engine compartment. Noise level was equal to best-in-class. Modular assembly assured accurate positioning of the blades on the windshield for smooth, streak-free operation.
Parallel-action blades provided a wiped area that met passenger car safety standards, there being no standard for trucks. Blades had the latest aerodynamic construction to assure effective wiping at highway speed. The back of each blade was cut away to reduce weight and let air pass through. In addition, the back had an airfoil shape that provided a downward force to counteract wind lift. This construction was more effective and had better appearance than earlier aerodynamic blade systems. Hook attachment of the blades to the arms was more stable than the previous pin attachment for smoother operation.
Bolt-on wiper arms assured accurate alignment of the blades to the glass. Alignment marks molded into the windshield interliner at the base of glass facilitate precise installation on every truck. The arms and linkage were also stronger than before to prevent packed snow buildup at the base of the windshield from damaging the mechanism. New over-center wiper arm hinges allowed the blades to stand off the glass for easy snow removal or cleaning of both glass and blades.
Dual washer nozzles on the cowl screen gave best-in-class glass coverage for rapid cleaning with minimal fluid usage. Fluidic nozzles provided a spray of fine droplets that oscillates rapidly across the wiped area. Nozzle spray patterns were fine-tuned for even coverage and appropriate droplet size. The washer fluid reservoir capacity is 0.8 gallon (3.0 liters) a 30% increase over 1996.
Driver Airbag System
The driver air bag had a conventional inflation system using the newest technology to produce a smaller, lighter module than prior systems. The module's lightweight aluminum housing had a multi-layer filter system to help contain any particulate matter that may be a by-product of the combustion process.
The bag and inflator were concealed beneath the steering wheel cover. The bag was 2 inches (50 mm) larger in diameter than the previous Dakota air bag to aid, in conjunction with the passenger air bag, in restraining the center front passenger.
The knee blocker was also the steering column lower cover. It derived its impact absorbing characteristics from an intensively developed honeycomb structure molded into the back of the polycarbonate-ABS blend cover - the same material from which the panel structure was formed.
A passenger air bag was standard on all Dakota models. The system used a hybrid inflator similar to but smaller than that used on Chrysler minivan. As with the driver air bag, the passenger air bag was made of controlled-porosity fabric. The passenger air bag module was mounted directly on the instrument panel's structural retainer, concealed by a molded door.
The passenger air bag worked in conjunction with a knee blocker and the Unibelt active restraint system to provide added collision protection for the front passenger. The knee blocker was also the glove compartment door. It derived its impact absorbing characteristics from the same type of lightweight honeycomb structure as the steering column lower cover. The loads were transferred from the door to the structural retainer by steel brackets at the sides of the glove compartment opening.
A centrally located electronic module controlled and monitored the driver and passenger air bags. Both air bags deployed simultaneously during a severe frontal impact. The electronic module included operating electronics, a collision detection sensor and system diagnostics. A single piezo-capacitive accelerometer in the electronic module discriminated between collisions of sufficient magnitude to warrant air bag deployment and minor bumps or normal operating conditions. The control system and sensors had been tested under severe conditions including snow plowing and off-highway operation to assure deployment of the air bag when needed and prevent inadvertent deployment. The module was mounted on the floor pan tunnel.
The air bag system was powered by two dedicated electrical circuits with gold plated terminals for maximum reliability.
Other safety issues
Roof pillar structural integration gave the new Dakota ability to meet the applicable roof strength safety standard. A bonded rear window, used on both standard and club cab bodies, contributed to the strength.
Stamped, one-piece, high-strength, low-alloy door beams helped protect occupants from side impact collisions. The beams conformed to the shape of the outer panel for added protection.
Dakota front seats were designed to absorb energy from rear impacts for occupant protection. All seats had high-back construction that deformed to absorb impact forces. Bench seat back hinges had inertia latches to hold the seat back upright during hard braking or a frontal impact, but allowed the back to fold forward under normal conditions. Bucket and 40-20-40 seat backs had recliner mechanisms on both sides that distributed impact loads to assure ample strength.
An Enhanced Accident Response feature was included with optional power door locks. Assuming an intact electrical system, it automatically unlocked the doors and turned on the interior courtesy lights if the crash was severe enough to deploy the air bags. The courtesy lamps turned on 10 seconds after the truck stopped (vehicle speed sensor output is zero or inactive) to avoid distracting the driver. They remained on until the ignition was switched off.
An illuminated entry feature was included with the remote keyless entry (RKE) system. Actuating the RKE transmitter or opening a door turned on the dome lamp and courtesy lamps in the overhead console, beneath the instrument panel, and around the ignition key cylinder, where installed. The transmitter had a range of approximately 23 feet (7m). It was powered by replaceable batteries.
Dakota offered a Vehicle Theft Alarm (VTA) with Sport and SLT equipment. The VTA monitored door key cylinder switches, ignition circuit and power door lock and unlock circuits for unauthorized entry. If a monitored condition was tampered with, the horn blows intermittently, headlights flash, the instrument cluster SECURITY warning indicator blinks, and the ignition was disabled to prevent theft of the vehicle. The horn would blow for up to 3 minutes. Headlight and warning indicator flashing continued for up to 18 minutes if the condition that triggered the alarm persisted and the system was not disarmed.
The VTA was armed by locking the doors with either front door power lock switch or with the RKE transmitter. The alarm was disarmed by unlocking the doors with the key or RKE transmitter but not by the power lock switch to deter theft by breaking a window. Attempting to circumvent the system by disconnecting and reconnecting the battery or unplugging the VTA controller would trigger the headlight and warning indicator sequence. Attempting to start the engine without disarming the system would trigger the full range of outputs. If the alarm was triggered during the last armed period but is no longer providing an output, three horn pulses sounded when the system was disarmed, alerting the driver of an attempted theft.
Optional power door locks operated automatically to secure the doors against unwanted entry and reduce the possibility of their opening in a collision. CTM logic initiates automatic locking when both doors are closed and vehicle speed exceeds 15 mph (24 km/hr) propelled by the engine, not coasting. If a door was opened, automatic locking would repeat when all required conditions were restored.
Door locking signals from either the RKE transmitter or the door lock switches would not lock the doors if the key was in the ignition when leaving the truck. CTM logic prevented transmission of the locking signal under those conditions.
The door locking mechanism was designed to discourage theft and illegal entry and door lock key cylinders have seven tumblers. Adding two tumblers from the 1996 level increased the number of possible key combinations to the same number previously provided by the ignition key cylinder.
1997 Dodge Dakota specifications
Specifications for the Dodge Dakota should be similar for 1998 and 1999; for 2000, the 4.7 V8 replaced the 318/5.2. 2001, 2002, 2003, and 2004 specifications should be similar except with regard to this engine.