If you have ever searched for a replacement part, a headunit upgrade, or a set of seat covers for a 70 Series and been confronted by a wall of alphanumeric codes, you are not alone. Toyota's chassis designation system looks cryptic at first glance, but it follows a clean and consistent logic that becomes second nature once you understand the formula. Knowing your code saves time, prevents costly fitment mistakes, and gives you a shorthand that every wreckers yard, parts counter, and 4WD forum speaks fluently.
The code is simply two parts joined together: an engine family prefix and a body-series number. Get those two pieces right and you can confidently cross-reference almost any component for a 70 Series, from filters and gaskets through to in-car electronics and interior trim.
At a Glance
- HZJ = 1HZ 4.2-litre naturally aspirated inline-six diesel, the long-serving 70 Series workhorse engine.
- VDJ = 1VD-FTV 4.5-litre turbo-diesel V8, introduced in 2007 and now discontinued in Australia.
- GRJ = 1GR-FE 4.0-litre petrol V6, found mainly in Gulf-market 70 Series variants.
- GDJ = 1GD-FTV 2.8-litre four-cylinder turbo-diesel, the current Australian range engine.
- Body numbers: 76 = wagon, 78 = Troopcarrier, 79 = cab-chassis (single and dual cab).
How Toyota builds the code
Toyota's chassis designations combine an engine family code with a body-series number. The engine prefix tells you the engine family, while the number that follows identifies the body style within that generation of the nameplate. For the 70 Series, those body numbers are 76, 78, and 79, representing the wagon, the Troopcarrier, and the cab-chassis respectively. Stack an engine prefix onto a body number and you have a complete chassis code: GDJ76, VDJ79, HZJ78 and so on.
HZJ: the 1HZ naturally aspirated diesel
The HZJ prefix denotes the 1HZ engine, a 4.2-litre naturally aspirated inline-six diesel that powered the 70 Series for many years and built a fierce reputation for reliability. It is not a powerhouse by modern standards, but its mechanical simplicity made it a favourite for remote touring where engine complexity is a liability. You will encounter HZJ75 codes frequently when searching for older cab-chassis and ute-based variants, particularly in the secondhand and classic 4WD market. Parts availability for HZJ vehicles remains strong, and the engine's longevity means plenty of well-maintained examples are still in daily use across rural Australia.
VDJ: the 1VD-FTV V8 turbo-diesel
The VDJ prefix belongs to the 1VD-FTV, a 4.5-litre twin-turbo V8 diesel that arrived in the 70 Series in 2007 and quickly became the enthusiast favourite for its combination of torque and refinement. The VDJ79 in particular, as a V8-powered cab-chassis, attracted a loyal following among tradies and touring enthusiasts who wanted serious towing capacity without sacrificing off-road credibility. Toyota has since ended V8 diesel production, so VDJ variants are now a finite and increasingly sought-after commodity. When shopping for accessories or electronics for a VDJ79 or VDJ76, confirming that code with your supplier is essential, as some components differ from the current GDJ equivalents.
GRJ: the 1GR-FE petrol V6
The GRJ prefix identifies the 1GR-FE, a 4.0-litre petrol V6. In the 70 Series, this engine is fitted primarily to vehicles destined for the Gulf region and certain export markets rather than the Australian domestic lineup. If you encounter a GRJ76 for sale locally it has almost certainly been imported. The GRJ is worth knowing about because petrol-engined 70 Series vehicles have a small but dedicated following, and their parts fitment can differ from diesel variants in ways that catch buyers off guard.
GDJ: the current 1GD-FTV four-cylinder
The GDJ prefix covers the 1GD-FTV, a 2.8-litre four-cylinder turbo-diesel and the engine powering the entire current Australian 70 Series range. The GDJ76 wagon and GDJ79 cab-chassis replaced their VDJ counterparts, and the transition brought with it a new generation of electronics, updated cabin architecture, and revised accessory fitment requirements. If you are buying parts, headunits, or steering wheel control interfaces for a new or recent 70 Series, GDJ is the code to quote. The current PVS Automotive 70 Series headunit range is engineered around GDJ fitment, with retained steering wheel controls a key feature of the installation.
Why the code matters when buying parts and accessories
Workshops and parts suppliers key fitment guides off chassis codes because even visually identical vehicles can have different wiring harnesses, dash configurations, and mechanical mounting points depending on their engine family. A steering wheel control interface calibrated for a VDJ may not communicate correctly with a GDJ's CAN bus. A headunit fascia cut for a pre-facelift HZJ dash may not align cleanly in a GDJ. Quoting your full chassis code, rather than just "70 Series", eliminates ambiguity and gets you the right component the first time. If you are unsure of your code, it appears on the compliance plate in the engine bay and on your vehicle's registration papers.
Quick reference: common Australian 70 Series codes
To bring it all together: HZJ75 is an older naturally aspirated diesel cab-chassis; HZJ78 is the Troopcarrier equivalent. VDJ76 is the V8 wagon; VDJ79 is the V8 cab-chassis, single or dual cab. GDJ76 is the current wagon and GDJ79 the current cab-chassis. GRJ76 is the petrol V6 wagon, rare in Australia. Bookmark this list, keep it handy at the parts counter, and you will spend far less time second-guessing compatibility on one of Australia's most enduring four-wheel drives.
