GVM upgrade in the ACT

[JBH Lurker Find all posts View Profile Close JBH]

For anyone who is trying to do a GVM upgrade in the ACT I have just completed one on a 2021 Prado GXL and now have a modification plate with a GVM 3250kg from OEM 2990kg.
It took approx. 3 months once contacting John Wilson from AKZ Engineering in Queanbeyan to getting a new modification plate. The car was tested at the Sutton track doing multiple brake tests from highway speeds along with swerve tests. These were done with 600kg of weight added (sandbags) and with all weight removed. All tests were recorded using a laptop measuring pressure placed on the brake pedal and g-forces. A detailed 43-page report including photos was then provided to give to the local inspection station. Once the car was thoroughly inspected and report read a new modification plate was supplied which then had to be engraved with the new details and attached to the car.
With a full tank and two passengers the car weighed 2700kg so I now have 550kg of payload available with the new GVM of 3250kg.
My build details were:
2021 Toyota Prado GXL with towbar, ARB summit/winch bar, Smittybilt winch, Stedi spotlights, Bridgestone desert duelers and Old Man Emu suspension (Kit EK2107C2).

[gunda Member Find all posts View Profile Close gunda]

I'm in the ACT and would dearly love a GVM upgrade, as I tow a hybrid van with a moderate ball weight. I have to be very careful about loading the Prado, even with the 3rd row seats removed, and as a consequence there have been very few mods. My problem is that I have a Kakadu with rear airbags. Some people in Qld seem to have managed to get one in a Kakadu with heavier duty AirBagMan airbags, and I've wondered how that would fly here.

Is it possible to ask how much the engineering report cost? Did you get any idea how much the lift contributed to the GVM upgrade? (I don't have a lift and am not really in the market for one, as I mostly want it for towing.) Was there any communication between whoever installed the suspension upgrade and AKZ?

I wonder what you have to do here to get an upgrade to 3500kg? Not that I need it, 250kg more would be sufficient.

[Piggy Water pistol pilot. Find all posts View Profile Close Piggy]

I wonder what you have to do here to get an upgrade to 3500kg? Not that I need it, 250kg more would be sufficient.

Speak to an engineer who specialises in suspension. Even on standard suspension a 10% GVM gain can usually be done (Even with Toyota airbags).

[gunda Member Find all posts View Profile Close gunda]

Speak to an engineer who specialises in suspension. Even on standard suspension a 10% GVM gain can usually be done (Even with Toyota airbags).

I had the impression that it was possible to get a GVM upgrade to the sum of the axle loadings, but wasn't sure of the details. It wasn't clear to me whether anything else had to be done in order to get such an upgrade. I looked at the specs of the Old Man Emu kit that JBH had installed, and it appeared to me that it was just a 40mm lift "for vehicles with Steel bull bar, winch and carrying loads of 200kg to GVM". Perhaps I just don't speak the language, but that didn't read to me as a GVM upgrade.

[JBH Lurker Find all posts View Profile Close JBH]

You can get a GVM upgrade to the max axle loading, 1450kg front and 1800kg rear, but you still have to pass the engineering test. I am no suspension specialist but with the original suspension and the weight they load up the car with it might not pass the test. The main reason we got the Old Man Emu suspension is when we were towing our 2500kg van the car was bum down and I wanted to be legal to carry the extra weight. The engineering report cost us $3200, but we can now tow and be legal, especially if we have to make an insurance claim. The suspension installer wasn't in contact with AKZ we just showed the details of what was installed. I was told that it is almost impossible to get a GVM upgrade to 3500kg (in the ACT) and I didn't need it anyway.

[gunda Member Find all posts View Profile Close gunda]

Thanks for those clarifications JBH. I don't have a problem with the Kakadu being bum-down, as the self-levelling air bags take care of that, at the cost of supposedly making it harder to get a GVM upgrade.

The people I bought the van from had an older 150 series GXL with the 1KD engine, and last year some time they got an upgrade to 3,500kg. This really puzzled me, as it was done in Newcastle to an ACT registered vehicle. Not sure how that worked.

Something else I don't understand. If you uprade the GVM to the sum of the axle loadings, and then load the vehicle up to the new GVM, don't you have to be careful about the weight distrubution? If it's too front or rear loaded, then isn't there a serious risk that you'd be over one or other axle loadings? Despite being within your GVM, you could get busted for that at one of these roadside weight checks that are becoming more common, esp in Qld.

[JBH Lurker Find all posts View Profile Close JBH]

Good point Gunda. You still have to be careful about weight distribution but I don't intend to load the car up to the full GVM. Before the upgrade when I was towing and adding the ball weight to the car it weighed 2950 kg with a full tank and my wife and I in it. That left us with only 40kg to spare. Now I don't have to worry so much if I happen to be slightly over.

[gunda Member Find all posts View Profile Close gunda]

I'm in pretty much the same boat. I haven't had the Prado and van combination weighed by one of the commercial weighing outfits, but have made multiple trips over the Mugga Lane public weighbridge separately and together, and have a Hayman Reese towball weight scale. My best estimate, since those things aren't super precise, is that I'd have roughly the same spare payload as you, or perhaps a little more, but not all that much. The towball mass is going to vary with the level in the tanks and how much firewood is in the carrier on the front of the van. I carry a fridge in the back of the Prado along with portable solar panels and miscellaneous other things, but have tried to offset by having the third row seats removed and a false floor installed. Also I spent up by putting a DCS lithium under the bonnet as my second battery, rather than an AGM.

I'm reasonably confident that I'd pass a weight check if they got me with a full tank as currently configured, but I want room for a few mods. I feel a little naked in the outback without a front bar and lights. Even a Smart Bar is going to eat into the small spare payload. Then there's a secondary fuel filter, catch can, tranny cooler, snorkel - none of these individually weigh much but everything adds up. Probably not another 260kg, but enough to push me well over 2,990kg fully loaded.

Thanks for sharing your experience. Very helpful.

p.s. Just to be clear, did the Old Man Emu kit make any contribution to the GVM upgrade, or was it just a lift kit?

[JBH Lurker Find all posts View Profile Close JBH]

The Old Man Emu kit did contribute to the GVM upgrade. We needed stronger springs and shockies to handle the extra load of bar/winch and 200kg springs on the back for towing.

[gunda Member Find all posts View Profile Close gunda]

Thanks again. I guess I need to talk to someone about my specific situation. I have no desire to fit a heavy steel bar and winch to the front. and the existing airbags prevent it sagging in the back when towing.