Holden Jackaroo (1981-1992)

HISTORY
The Isuzu-built Jackaroo is sadly no longer with us after being replaced by the Holden Adventra as the company's preferred machine.

The Holden-badged Jackaroo was first produced by Isuzu in October 1981. The original boxy shape continued - with various mechanical and cosmetic upgrades - until May 1992, when the current body shape was introduced on top of new chassis and powertrains.

The original machine came with two-door bodywork, in two wheelbase lengths and with a choice of petrol or diesel power.

Interior trim levels in 1981-1983 models were basic vinyl, although a fashion pack option introduced cloth seat covers, extra instruments, head restraints and carpet. Steering was manual only.

The petrol engine was a two-litre, OHC four, with 65kW at 4600rpm and 140Nm of torque at 3000rpm. The naturally aspirated diesel displaced 2.2lt and had 45kW at 4000rpm and 130Nm at 2200rpm. The diesel boasted a quick start system, in contrast to the slow glow pre-heaters common in 4X4s of the day.

The standard transmission was a four-speed, non-overdrive box, with a two-speed transfer. The front diff was chassis-mounted, connected via half shafts to manual free-wheeling hubs. The rear axle was a live unit, suspended by leaf springs and fitted with a limited-slip centre. The front end used wishbones and torsion bars.

Braking was by way of front discs and drum rears with vacuum assistance.

STEADY UPGRADES
In late 1983 Holden announced an upgrade, with power steering on the LS model, an auxiliary tank to double fuel capacity to 100lt, ventilated front discs, a revised instrument panel, a centre console and a split rear seat.

The box-shaped Jackaroo was upgraded in mid-1984, when the naturally aspirated diesel was replaced by a turbocharged version, with 10kW more and an increase in torque to 170Nm.

In 1985, a five-speed transmission was adopted and the petrol engine's capacity went up to 2.3lt. In July 1988, the petrol engine was upgraded to 2.6lt, with fuel-injected outputs of 88kW and 195Nm, while four-wheel discs were added.

In 1989, the 'old box' got its last upgrade, with the introduction of new powertrains. The two-door was confined to 2.6lt petrol power, but the four-door came with the petrol engine, or a new direct-injection 2.8lt turbo diesel, with 74kW and 225Nm.

Both engines drove through a five-speed manual box, or an optional four-speed auto behind the petrol version. Track was widened and gas-pressurised dampers fitted, but the suspension layout remained as before.

In May 1992 the new Jackaroo was released. This completely new vehicle was aimed at the large-wagon end of the market and boasted greatly improved performance. The new engines were a 3.2lt petrol V6 with 130kW and 260Nm, and a 3.1lt indirect-injection, intercooled turbo diesel, with 84kW and 260Nm.

The driveline reflected some cost-cutting at the financially strapped Isuzu factory - by then under General Motors' control - and stayed with part-time 4X4 while the opposition had moved into full-time 4X4. However, the former leaf springs had given way to rear coils, in conjunction with torsion bar fronts.

The 1992 body change gave the Jackaroo greatly-improved space and comfort over its predecessor. Rear seat legroom was particularly good. The Isuzu quirks remaining were dashboard knobs to perform functions that in other makes were done by steering-column wands.

Another strange arrangement was a vertically split rear door, which should have solved the problem of pulling the weight of a spare wheel each time you opened the back - but Isuzu-GM designed the door overlap so that you had to open the heavy door first!

The upmarket V6 Monterey was introduced in January 1994, with on-demand 4X4 and a standard automatic transmission.

In July 1995, the range was revamped. The SE specification level was changed to include alloy wheels, power windows, cruise control and central locking. At the same time, two-tone paint schemes were introduced to help reduce the boxy exterior appearance.

The interior was given a much-needed redesign, with a new dashboard, centre console and control layout, including a four-spoke steering wheel and stalk controls for lights and wash/wipe functions. The interior colour scheme was softened to light grey and new fabrics for the seat covers were introduced.

The post-1995 Jackaroo had generally good ergonomics, with well-placed controls and easy entry and exit. Further upgrades occurred in October 1996, in September 1999 and most recently in October 2001.

The 1997 Jackaroo range revision took the offering down to seven models, from the original 13 models launched in 1992, and the subsequent cut to eight models in 1995.

In June 1998 a new 3.0lt turbo-diesel engine was introduced, featuring Caterpillar's HUEI injection system. This high-tech engine put out a market-leading 118kW and 333Nm of torque.

POINTS TO WATCH
Jackaroo petrol models don't have any glaring faults, other than weak CV joints in very early models and cylinder-head problems in the early 2.6lt petrol fours.

The post-1998 3.0lt turbo-diesel can suffer from leaking O-ring seals on the injectors, particularly if the wrong engine oil is used. (The hydraulic injection system relies on correct oil viscosity to operate it.) There was also a recall in 1999 on diesel O-rings.

Most in-service problems arise from over-use or abuse of a vehicle that has limited bush-travel specification. The original Jackaroo was never intended to mix it with LandCruisers, Patrols or Land Rovers, but many owners tried to do just that.

The latest Jackaroo is more heavily built than its predecessor, but is still in the durability class with Pajero and Prado; not the heavy-duty 'square riggers'.

It's wise to have a professional inspection of any used Jackaroo, and post-1998 turbo-diesels must have proof that the O-ring sealing problem has been professionally resolved.

All Jackaroos have marginal ground clearance and so are more likely to show evidence of offroad damage if they've done much bush work.

GMH's optional long-range tank for the Jackaroo was a Brown Davis auxiliary, and the transfer pumps supplied with that kit are notoriously unreliable. One of the main problems facing Jackaroo owners is the relatively small pile of used parts available from wreckers. For instance, if you bend an axle or break a transmission or diff, you might find yourself up for the cost of new parts, because there just aren't enough used bits out in the market.

The best used box-shaped Jackaroo buys are post-1989 models, which have quite good on-road performance and good trim levels. The trick is to get one that's done little or no offroad work and treat it kindly. The 1989-1991 turbo-diesel engine was the Rodeo powerplant, which was the most frugal Japanese diesel on the market back then.

Post-1992 models have much more interior space than earlier models, and more performance. The turbo diesels had more grunt than the previous versions, but used more fuel. We've never done better than 12 litres/100km out of a Jackaroo turbo-diesel, and the V6s use around 15 litres/100km.