Holden Jackaroo Review 1998 Model
The Jackaroo's journey had not always been a smooth ride, with early models copping plenty of criticism, but this was about to change. In 1997 Jackaroo doubled its sales figures over 1996 and Isuzu set a target of 3400 for 1998. And in 1998 the Jackaroo received a big power boost from both its petrol and diesel engines.
The highlight was the new 3.5-litre V6 engine, which developed 158kW of power at 5400rpm - 21 per cent more than its predecessor - and 310Nm of torque at 3100rpm, an increase of 19.2 per cent.
The 1998 Jackaroo 3.0-litre diesel engine featured state of the art engine and fuel system technology that brought new levels of sophistication and performance to the medium 4x4 wagon market. The 3.0-litre turbocharged four cylinder diesel's power output of 118kW at 3900rpm was 40.5 per cent up and its maximum torque of 333Nm at 2000rpm was 21 per cent up over the unit it superseded. This meant that the Jackaroo was easily the most powerful vehicle in its class.
Isuzu also moved the Jackaroo squarely into the luxury recreational market, offering the new 3.0-litre diesel in the mid-range SE model, along with a host of additional features and equipment, including seven seats.
The 3.5-litre V6 petrol engine featured a variable intake manifold system designed to enhance engine breathing and top end power. Sequential fuel injection improved combustion while reducing exhaust emissions. A high energy ignition system provided smoother power delivery. It featured six new design integrated coil modules. Each was attached directly to its respective spark plug, eliminating the separation ignition module and high tension wiring found on conventional spark ignition systems. Engine construction was also substantially modified and simplified with the elimination of hydraulic valve lifters, chain tensioner, water bypass and the external oil cooler.
Camshafts were now gear and not chain driven. The gear drive featured scissor gears for elimination of gear backlash and quieter operation. The camshafts acted directly on the valves, enabling a compact head design with fewer moving parts. Friction was reduced, contributing to improved fuel efficiency.
The new 3.0-litre turbodiesel was actually down in capacity from 3.1-litres, but gained a massive 40 per cent increase in power up to 118kW at 3900rpm. Torque was also up 28 percent to 333Nm at 2000rpm. The four cylinder intercooled turbo employed four valves per cylinder, double overhead camshaft with direct acting valve mechanism and high pressure electronic fuel injection system. The system was the same as used by Caterpillar, and delivered increased performance and efficiency.
To cope with the increased power the Jackaroo gained a new five-speed manual, all synchromesh transmission, recalibrated four-speed auto gearbox and heavy duty rear axle. A single Powertrain Control module controlled both the engine and auto transmission. The previous Jackaroo employed separate modules for engine and transmission. The new arrangement allowed for simplified wiring, reduction in cost and weight and better integration of engine and transmission functions. In practice the engine/transmission combination was superb.
A selectable 4WD system with manual locking front hubs was retained for the Jackaroo and SE models. The range topping Monterey came with a torque on demand system with shifty on the fly 2WD-4WD High - 2WD. The system was activated by a dash push button, allowing the driver to select between 2WD and 4WD High while driving at speeds up to 100km/h. Shifting between 4WD High and 4WD Low range was achieved using a conventional floor mounted shifter.
Shifting into 4WD automatically engaged the torque on demand traction control system. The TOD module continually monitored the forward and rear propeller shaft speeds, redistributing torque on demand as a difference in propeller shaft speed indicated a loss of traction at one of the axles. The system could apportion torque smoothly and progressively up to 100 percent rear wheel drive, through to 50/50 front and rear wheel drive. A dashboard indicator showed the percentage of drive being applied to the front and rear wheels. In 4WD the Monterey functioned as a rear wheel drive vehicle on dry paved roads, whereas on winding or wet gravel roads, torque was shifted to the front wheels as conditions demand.
The cruise control system on petrol models was recalibrated, with movement of the auto shifter disengaging the cruise function.
Suspension was carried over from the previous model, using the same four-link rear coil suspension and independent front set up. With adjustable torsion bar springs, stabliser bar and gas shockers, this system provided predictable, responsive handling.
The 1998 Jackaroo gained exterior modification, distinguished by new frontal styling, including new grille, headlights, and smoother bumper and alloy wheels.
Inside air conditioning was standard across the range, and seating for seven was standard on SE and Monterey models. Other changes included new lighter interior trim colouring, an LCD type odometer with trip meter, and two new body colours.
The Jackaroo also took a quantum leap in safety with all 1998 models fitted with driver and front passenger air bags. The Monterey gained a Bosch ABS antilock braking system, fully calibrated to Australian conditions. The Jackaroo benefited from an upgraded immobilization system, with the Monterey and SE models having remote keyless entry and an anti-theft alarm.
On the road, the 3.0-litre turbodiesel mated to a 5-speed transmission delivered great ride, handling and performance. This model Jackaroo was a first rate wagon.
Petrol Diesel
Engine V6 DOHC petrol 4-cyl Intercooled turbodiesel
Displacement 3.5-litre 3.0-litre
Power 159kW @ 5400rpm 118kW @ 3900rpm
Torque 310Nm @ 3100rpm 333Nm @ 2200rpm
Transmission 5 speed manual, overdrive 5 speed manual, overdrive
4-speed auto, overdrive
4WD system Jackaroo/SE - selectable 4WD system with manual locking front hubs
Monterey - Torque on demand electronically controlled torque split 4WD system with shift on the fly 2WD-4WD high 2WD.
GVM 2600kg
Payload 1900kg 1940kg
Max towing capacity 2500kg
Fuel tank 85 litres
Dimensions Length 4660 x Width 1745 x Height 1840mm
Wheelbase 2760mm