The Brief
After my Jeep JK I needed a change. The Jeep was impressive but had a ground clearance problem — I was regularly sitting on the belly panel on 37s. The JK's geometry just isn't right for serious rock work without going to 39s or bigger.
In 2021 I had the chance to drive a Hilux on technical terrain several times. The older Hiluxes have a simplicity and a geometry that suits rock crawling well — low, narrow, light, with real solid axle travel potential if you build them properly. I found a 1985 Y67 Extra Cab that had just been restored by a mechanic, bought it, sold the Jeep, and started the build.
I knew exactly who I wanted to build it: Garth Hannaford. Garth has been building off-road vehicles for over 33 years. He's not just a fabricator — he understands geometry, suspension dynamics, steering, and engineering compliance. What was planned as a six-month build took two and a half years. What came out the other end is something I don't think has been built before in Australia — at least not in a fully road-legal, fully engineered form.
Key Specifications
| Engine | 3RZ 2.7L 4-cylinder, 5-speed manual |
|---|---|
| Transfer case | Atlas 4:3 (independent F/R/both selection in low range) |
| Diffs | Jeep JK G2 housings, 4.88 gears, ARB air lockers |
| Axles | 35-spline chromoly, front and rear |
| Steering | PSC hydraulic (Toyota 80 Series steering box) |
| Suspension (rear) | Slide box (250mm travel), Rancho 9-stage adjustable, 15" travel |
| Tyres | 37" BFG KM3 Mud-Terrain |
| Winch | Rear-mounted Sherpa LB12000 |
| Brakes | Dual-diaphragm JK system, 330mm rotors |
| Weight | ~1,700 kg |
| Registration | NSW Classic Vehicle Scheme |
Engineering First
From day one, the engineer was involved — not after the build was done. Every material thickness, every bolt diameter, every component choice was submitted to and approved by the engineer as we went. The testing process was extensive. The vehicle went to Canberra with approximately 800 kg on board and passed swerve tests, brake tests, and a brake plate test at approximately 98 km/h. The brake plate test checks stopping efficiency on all four wheels independently, with and without the brake booster — a three-hour process when done properly.
This is possibly the only road-legal 37-inch Hilux in Australia. Given how far engineering standards have moved away from certifying modified 4WDs, I doubt another one will be built.
Platform and Drivetrain
The Atlas 4:3 transfer case is the key to how I use this vehicle. It gives independent shift between front drive and rear drive — front-wheel-only for descending steep drops, rear-wheel-only for specific situations, or full low-range front and rear. For rock crawling, that level of control over drive delivery is genuinely useful.
The diffs are Jeep JK G2 housings with 4.88 gears, ARB air lockers, and 35-spline chromoly axles front and rear. Massively overbuilt for the weight of the vehicle — deliberately. The brake system is also from the JK: dual-diaphragm Toyota 80 Series brake booster, 1-inch non-ABS master cylinder, and 330mm JK front rotors.
Steering
Full PSC hydraulic power steering — a 1,500 PSI, 2.8 GPM TC pump with a Toyota 80 Series steering box, and a PSC ram (6.5" stroke, 2" bore). All steering links are 4130 chromoly. Garth had to relocate the alternator to the top of the engine bay and move the power steering pump to the bottom so the reservoir is gravity-fed — no oil starvation on steep climbs. That kind of detail is what separates a vehicle that works properly from one that develops problems the first time you use it hard.
Suspension
The Hilux runs a slide box rear suspension system instead of shackles. A standard Hilux shackle gives about 120-130mm of travel. The slide box gives 250mm, and the travel is smooth and linear — a Delrin bush running in an oil-impregnated housing means no binding and no lubrication required.
Shocks are Rancho 9-stage adjustable units with 15" travel. The rear diff is trussed to prevent axle wrap under hard torque.
The philosophy: minimal lift, wide stance, low centre of gravity. More suspension travel doesn't always mean more capability — on very technical terrain, excessive travel can cause the rear axle to go under obstacles rather than over them, which creates instability.
Winch
Rear-mounted Sherpa LB12000 (12,000 lb), 6.6 HP motor, three-stage planetary gear system. The winch cable runs forward via a tube through the cabin. Weight distribution was a significant consideration throughout the build — with the engine at the front and a lightweight body, keeping the rear weighted was important.
