My FGB71 build


New member
That really looks good, those tyres have a very large load rating so you won't be needing to restrict either of your axles.

I saw six wheels, but couldn't find the sixth on the truck, is it not fitted yet?

As you don't have low range, which is a blow. Have you considered adding an Automatic Torque Bias (ATB) LSD to the front differential to give you as much pull as possible? Made in your country by Quaife.

We have an Isuzu NPS 300 75-155 (Australia) fitted with one of these in the front differential, unbelievable is probably the best description. Our truck was also started in 2019 and stretched out into May 2020 by COVID-19 as well. Having recently done some interesting stuff on loose surfaces, as well as quite steep loose surfaces in low range, I can say I don't think I would have another truck without one fitted.

Whenever the front wheels are locked and 4WD engaged, the ATB LSD differential is just there doing its stuff. I didn't think the difference was that much over an open differential, but after travelling on a hilly very loose gravel-shale type of track with another similar truck with the standard open front differential, the owner of the other truck just asked, "how much does that front diff cost?"
That LSD looks like a good bet – once the build is finished and if under budget, I’ll run it past my financial advisor (‘er indoors). I’ll have to enquire with Quaife that it is compatible with the Euro diff (4.8 rather than the Oz 5.2) – hopefully the housing and cage is the same, and it’s only the gear-set that’s different.

I got an extra rim and tyre made just for safe keeping, to save on having the hassle of getting another rim made down the line if I ever damaged one. I had intended to travel with only one spare, as our travels will be 1st-world only where tyre shops are plentiful, off-highway rather than full off-road, and also to keep weight down.

Talking of weight, I’ll have to re-plate the truck for here in the UK. With the original duals, the tyres out-rated the diff max, but the singles, even at 138 (4720kg per pair) are a 1000kg down on the diff. So the diff max has to be down-plated from 5700kg to 4700kg to match the tyres, which is ok as the bare chassis rear axle weight is 1000kg and the bare box and subframe is under 1000kg – that leaves at least 2700kg for the interior, water and payload . If the truck is well under 6000kg in full tour mode (including the proverbial 'kitchen sink' the missus will want to bring), I’ll down-plate the GVM to 6T – I’m a Kiwi who hopes to return home eventually, and in NZ you can drive up to 6T on a car licence. In the UK , a C1 licence for 3.5-7.5T is required, and it is not transferable like the car licences are between select Commonwealth countries.


Active member
NZ you can drive up to 6T on a car licence. In the UK , a C1 licence for 3.5-7.5T is required, and it is not transferable like the car licences are between select Commonwealth countries.
When i moved out from uk to NZ i transfered all of my driving licence entitelments to nz licence but for the class2 3 4 and 5 you had to sit the theory exam only to show u understood the nz highway and how it relates to heavy goods .

Also with the 6 ton rule i am pretty sure there is a max length involved although i cant remember what it is. I had a light weight canter a while back that was in the correct weight but was 50mm over length so hit class 2 :-(
Ah, well, I still have a current NZ licence as well as a UK one, so I'm hoping no test required to transfer my UK HT(HGV) licence?

I had to go check the NZ regs. Our truck is 6.2 metres from front bumper to spare tyre, so appears to be in the bubble - it's actually shorter than a LWB Sprinter van. Annoyingly it's 200mm too long for the cheap rates on the Scottish highland ferries though, and will be charged for an 8 metre motorhome if I can get the reg papers changed to 'motorcaravan', or full commercial rate if not.


New member
Late last year, I participated in a comparison test between our Isuzu light truck and a reasonably standard ute, albeit one with a rear differential lock. The idea for the comparison is to give an idea of what is available in Oz outside of utes, which in many cases people are running up to and over their GVM and maybe when they consider their next vehicle for touring they may wish to seriously consider going the light truck route. Most people in Oz think light trucks are reasonably useless for doing stuff in the bush, unless it's a Unimog or MAN, whereas the truth is that the Fuso Canter and Isuzu NPS offer a reasonable alternative at a more reasonable price after modifications like super singles, at a minimum, are done.

Our own situation is one where we ran our slide-on camper on our Isuzu D-Max cab chassis tray back ute for 10 years, before the ute started to fail. Endless corrugations, some sand hills and sometimes very sandy tracks, all added to the workload of the venerable D-Max to the point that even with some extensive modifications it no longer cut the mustard. The ute was my daily driver around town with the camper parked on our property when not touring. Plus, we were always right on the limit of our weight carrying capacity.

Having been retired for 8½ years now, circumstances have changed and a more permanent situation was on the cards. A motorhome like what are doing would be wonderful, but we had a perfectly good camper which we designed and had built 11 years ago. So we opted for a new truck through ATW in Qld with a tray and bolted the camper to it; not perfect, but it should see us out.

Some discussion about what could be useful and what should really be considered necessary, zeroed in on a couple of modifications to the standard truck. The ATB LSD was viewed as virtually mandatory if one was serious and may get into situations where one needed all the traction one could muster. In various parts of this comparison you can see the front LSD doing its bit, but at 20' is probably where the front differential is shown at its best. This is a manual gearbox unit and in all situations, except when amongst the trees, I never touched the clutch going up or down. Careful throttle application negates that need and coupled with a large very unstressed engine (5.2L) it recovers from near stalling at idle speed under heavy load easily.

On the day of this comparison, I weighed the truck immediately prior, front axle 2780kg, rear axle 2940kg total 5720kg. Our tyres are rated to 1950kg each, so the rear axle is limited by the tyres to 3900kg, while the front axle is rated to 3100kg and is limited by the axle rating, giving us our legal GVM of 7000kg.