Is this Australia’s toughest Toyota LandCruiser camper conversion?

EarthCruiser’s first Extreme XTR330 is exactly that: extreme. A true go-almost-anywhere motorhome, with the expected top-shelf EarthCruiser home comforts, it’s built on a greatly modified LandCruiser 79 Series cab/chassis.

But if you haven’t got a big bag of money, don’t even think about annoying Wollongong, NSW-based EarthCruiser for your very own Extreme XTR330 6x6: it’s around double the price of a ‘normal’ EarthCruiser Extreme 4×4… and they’re not cheap. 

The 2023 6x6 XTR330 just completed by EarthCruiser was developed in conjunction with Bob James’ 6×6 Australia; another NSW off-road specialist that’s well known for its innovative 6×6 conversion on ute and light truck cab/chassis.

Big-time conversion

The 6×6 Australia conversion is similar to the design approach used by some European OEMs, employing a single main prop shaft – not the power take off used by some after-market converters – and a load-sharing beam that distributes rear tandem weight evenly between the rear axles.

Although the EarthCruiser XTR330 6x6 motorhome is based on the Toyota 79 Series, there isn’t much left of the original beast’s chassis and running gear. The cab looks standard, but the rear wall has been cut to allow a crawl-though into the motorhome body. 

The chassis under the cab remains, albeit with considerable ‘flitching’ for additional strength, but the chassis aft of the cab has been extended and ‘joggled’. This frame ‘waisting’ is done using ‘lobster back’ tapering and joining, and is CAD modelled and CNC laser cut.

This aft narrowing of the custom box-section chassis rails also allows installation of a James walking beam that provides 50:50 weight distribution between the two rear axles and space for outboard-mounted air springs, for optimal handling and sway control.

Also limiting sway are military-spec anti-sway bars with an in-cab remote disconnect function that allows the sway bars to detach and provide more axle articulation off-road. 

Needless to say, the narrow-track standard Toyota rear axle is gone and replaced by two fabricated axles, with chrome-moly half-shafts and 3600kg capacity apiece. Rear axle track matches the front axle dimension (a task that still seems too difficult for Toyota to manage!). The front axle is a fabricated design, with a load rating of 1980kg.

The rear diff centres are Ford 10-inch and 9-inch, respectively, fitted with diff locks and controlled by a power divider that lets the third axle ‘idle’ unless a loss of traction occurs. All three diff locks can be engaged simultaneously, if required.

Some 6×6 conversions make turning circles vast, but the James design incorporates VRRS – Variable Ratio Rear Steer –  that provides variable steering assistance from the rear bogie, based on the radius and speed of the turn.

Air suspension is done by six air springs, with custom-designed Bilstein dampers. A side benefit of the air suspension is automatic 100mm load levelling when travelling and up to 250mm static. The air springs are fed from 52L of on-board compressed air storage.

The XTR330 also has four hydraulic rams for self-jacking on slopes.

The chassis and axle/suspension additions also see the GVM increase to 7000kg (under the second manufacturer SSM scheme that’s nationally recognised, but painfully slow in process, despite the much-vaunted new ROVER initiative).

EarthCruiser retains the standard V8 powertrain, with a choice of the Toyota five-speed manual, with heavy-duty clutch, or a six-speed Aisin auto from the LandCruiser 200 Series.

As this writer knows only too well, a wheelbase extension compromises belly clearance. (Our 75 Series 4x4 has a wheelbase extension to 3700mm and that sometimes sees the belly touching the deck.) The first XTR330 has an even longer ‘mean’ wheelbase of 4130mm (measured from front axle to centre of rear axle group), so belly clearance is potentially debilitating.

There’s a simple if somewhat pricey solution for the latest EarthCruiser build: portal axle hubs. A portal hub is a ‘drop box’ with a gear set in each hub that lowers the axle centre line, thus allowing the axle to be mounted higher in the vehicle. At the same time, some gear reduction is included, thus lowering the torque loads on the axle half shafts.

In the case of this XTR330, the ground clearance under the axle diff bowls has been increased by 120mm to 390mm and the gear reduction in the hubs is 16 per cent. The lowest chassis point is 610mm above level ground. Total vehicle height is 2600mm at suspension ride height.

Portal hubs have a side benefit: making it easy to accommodate an air feed though the hubs, into each tyre, allowing inflation and deflation via touchscreen controls while the vehicle is in motion. The CTIS (Central Tyre Inflation System) reacts to road speed by implementing automatic pressure changes, based on road speed.

The downside of portal hubs is heat caused by gear friction and this has been countered by fitment of remote oil reservoirs for the hubs.

The wheel ends are finished off with upgraded brake packages, backed by hydraulic brake boosting. The 17-inch EarthCruiser Exclusive forged aluminium wheels with dual inflation valves for the 35 x 12.5-inch Federal Xplora Mud terrain tyres are 137Q load rated (2300kg per tyre). Toyota’s 3500kg towing capacity is unchanged.

The gang at EarthCruiser are hands-on remote area travellers, so they know exactly what’s required for extended trips away from support. This degree of necessary equipment starts with tank options for fuel and water, including twin 275L water and fuel tanks, plus a 27L grey water tank. An integrated high-pressure water blaster delivers a 1500psi stream.

There’s also an optional ‘Arctic’ package, for operation down to minus 40 degrees Celsius including heated water tanks and batteries, and a drying compartment for clothes and wet goods.

The spartan Toyota cab is upgraded in the form of repadded and leather-reupholstered driver and passenger seats, plus there’s a leather-covered console, EarthCruiser-quality cab insulation and Clearview power-fold electric mirrors. There are also optional cab seat heaters and multiple USB outlets.

Behind and above the cab sits EarthCruiser’s one-piece, infusion-moulded structural foam roof, closed with double seals, and bonded to moulded, structurally insulated foam walls and floor. The insulation is rated for -30C to +70°C ambients.

A moulded, structurally insulated and sealed entry door is fitted with a deadlock and all the body latches and locks are flush-mounted or recessed. Access is made easy by EarthCruiser’s exclusive, automatically retractable cab entry steps.

A triple-layer block-out roof curtain incorporates PVC windows, insect and full privacy screens. 

Although best reserved for sleeping two, a third person can be accommodated inside, while the XTR330 also features four seat-belted positions: two in the cab and two in the camper.

Body skirts with four lockable toolboxes are also fitted, and a lockable, pass-through rear hatch allows storage of items such as fishing rods, skis and camp chairs.

The camper also gets leather dinette seats, CNC-routed Corian bench tops, a stainless steel sink with purified drinking fountain and taps, instantaneous diesel hot water, diesel cabin heating, an electric-slide-out Thetford chemical toilet ensuite, and internal and external showers.

The XTR330 also features a lithium battery system for starting and house batteries – a whopping total of 1110Ah all up, or around three to five times what’s normally provided in motorhomes.

Also standard are 810W mono-crystalline solar panels, with room for up to 1152W panels. There’s also a 3000W Victron Inverter with 6000W peak power and a 50A Multi Country (variable frequency and voltage) Victron battery charger.

A 200A high-output, fully sealed and water-cooled brushless alternator (mine spec) replaces the ’Cruiser’s standard alternator.

This high-capacity electrical system means there’s no need for any LPG on the ‘gas free’ XTR330. Even the roll-out BBQ is 240V electric and the kitchen’s 3500W two-plate induction cooktop is joined by a microwave oven.

The twin fridges are a main 122L model and a 68L rear fridge/freezer.

There’s also ample battery capacity to run a 12V split air-conditioner (90A/1800W/5800BTU/h) without the need for plug-in mains power.

Other electrical equipment includes a chargeable cordless mini wet and dry vacuum cleaner; a chargeable toolkit with chain saw and impact wrench; and a 12V 2160W continuous-duty air compressor that provides 14CFM at zero psi and 8CFM at 100psi.

The first custom-built XTR330 is also equipped with a pair of GME XRS connect UHF radios and Hella HID driving lights, but other options are available. 

The purpose-designed recess in the nose of the camper moulding also neatly houses a 52-inch, dual-row, curved Roadvision LED light bar, while fog lights are integrated into the bullbar.

Other exterior lighting includes 360-degree flood lights on all sides including the rear of vehicle, with an ‘emergency lighting’ function. An optional internal/external security camera with 24-hour DVR system is also available.

A SpaceX Starlink system is also wired in, offering global internet connection. The satellite dish is flush mounted with the roof, to prevent damage. There’s also an optional Cel-fi cellular phone signal booster.

The touchscreen Garmin head unit features digital switching of all motorhome functions with wireless capability range of up to five metres. It also has an inbuilt pitch and roll meter and TPMS display, and comes loaded with Hema Mapping plus audio with radio, AUX, USB and Bluetooth connectivity. It plays audio through an additional speaker system in the camper. 

A DVR/GPS/4G solid state digital video recorder is also on the options list, along with cellular hot spot and GPS tracking in real time, with 60-day recording loops.

The Garmin system interfaces with three 10-inch touchscreens, two of which have removable wireless docks.

Protective kit includes a hammer-tone winch-compatible steel bullbar with steel scrub rails and side steps, colour-coded to the bullbar. Two, front and rear, 13,000lb 12V electric winches are also fitted, along with heavy-duty front and rear recovery points.

There are two spare wheel carriers with electric lifters, to help make tyre changes effortless.

A dual-purpose Maxtrax/firewood box carries up to four sand ladders and a load of firewood simultaneously.

Given the incredible equipment levels in this very first EarthCruiser XTR330 6x6 motorhome, it’s possible we’ve missed something, but we can’t think what that could be. And yes, it does have a kitchen sink…