GVM Upgrade – When more is a burden

Submitted: Friday, May 15, 2015 at 11:23
ThreadID: 117860 Views:5214 Replies:7 FollowUps:15
This Thread has been Archived
When I upgraded to my current vehicle, dare I say the new “Landy”, a Toyota 79 Series Dual Cab, I customised it to be used for long-range and remote travel.

This included having a canopy specifically designed for the vehicle to carry a range of equipment; long-range fuel tanks and ability to carry sufficient water and supplies.

All this comes with a weight penalty.

Configured in long-range touring mode the vehicle comes in at approximately 3,500/3,600kg with full fuel as it heads down the driveway with Mrs Landy, TomO, and me in the cabin.

The actual weight is in contrast to a GVM of 3,300kg off the factory floor.

This was corrected from the outset by upgrading the GVM to 3,900kg using a Lovell’s GVM upgrade kit, which has served the vehicle well so far without fault, but dare I tempt fate by suggesting that?

Toyota's combined axle weight limitation of the vehicle is 3,780kg, which equates to the GVM, and one can see that the Lovell’s approval is above the manufacturer’s combined axle weight limitation which has some consequences. Lovell’s have an approval to increase the front and rear axle loads above Toyota’s by 60kg respectively.

Many in the industry have questioned how the modification was ADR certified for use on this model vehicle given it surpasses Toyota’s axle rating, but it is all in order. Lovell’s have the approval which had to go through a rigorous testing program, but it is something to be aware of if using a Lovell’s upgrade on a Toyota 70 series vehicle.

In its current configuration my vehicle cannot be loaded to its maximum GVM as the load limiting factor is the approved rear axle weight where naturally much of the load is carried. As highlighted earlier this was increased with the GVM upgrade, however as for most vehicles, the total GVM is one factor for loading, limitations on each axle is another.

And in many cases this means some of the excess load carrying ability is available on the front axle only.

I am currently in the process of having the Tru-tracker rear wheel offset correction installed, which is a fully engineered and ADR compliant modification to correct the large offset between the front and rear wheels. However, this is approved for use on vehicles with a maximum GVM of 3,780kg which, not surprisingly, is the manufacturer’s combined axle load carrying rating of the vehicle.

In fact, if you look at all other GVM upgrades offered for this vehicle, none are above the combined axle weight of 3,780kg with the exception of Lovell’s.

You can read more about the Tru-tracker modification on the company's website.

The solution to resolve the “paper work” issue and it is essentially a paper work issue, albeit a bit of as “burden” is to have the GVM re-rated downwards to 3,780kg. This will be done at the time the engineer signs-off the Tru-tracker modification.

But if considering a Lovell’s GVM upgrade, or for that matter any type of upgrade it is worth giving thought to under-intended consequences.

Possibly, more is actually a “burden”…at least it was with my GVM upgrade!

Cheers, Baz – The Landy
Back Expand Un-Read 1 Moderator

Reply By: Robin Miller - Friday, May 15, 2015 at 13:47

Friday, May 15, 2015 at 13:47
Understand Baz but I think one should really look at each item carefully with a view to "Is it really necesssary" , I like my policy of not adding anything unless weight is removed elsewhere as a cars ability to do the mission includes not just GVM but stress on every component from brakes to forces in the driveline.

I'm designing a camper at the moment which will have a maximum loaded weight of 750kg (with a trailbike) and I can't see any need at all for such things as trailer brakes , spare wheel or load re-aranging things basically because overall weight by design will be 25% of cars weight.
Robin Miller

My Profile  Send Message

AnswerID: 553790

Reply By: AlbyNSW - Friday, May 15, 2015 at 14:10

Friday, May 15, 2015 at 14:10
I hear you Baz
I have a very similar setup to yours including the GVM upgrade and it is fine but after doing a couple of lightweight trips without my canopy, just a swag and some gear in the tray the vehicle feels so much more nimble
I have just taken delivery of a half tray canopy to replace my current one in a bid to shed some kilos

I have found we have more room than we need anyway so thought I would reduce my size

I could drop a few kg's myself to help the cause as my doctor said I am exceeding my GVM
AnswerID: 553792

Follow Up By: Michael H9 - Friday, May 15, 2015 at 14:56

Friday, May 15, 2015 at 14:56
I think it is GPM (Gross Person Mass) for us Alby. Baz was only breaking it down to axles...I'm getting concerned about the increased load over the wheel I happen to be sitting closest to. Cheers
FollowupID: 839672

Follow Up By: vk1dx - Friday, May 15, 2015 at 16:20

Friday, May 15, 2015 at 16:20
Is that the "large gross area" just above the belt line that pushes on the lowest part of the steering wheel.
FollowupID: 839677

Follow Up By: The Landy - Monday, May 18, 2015 at 07:59

Monday, May 18, 2015 at 07:59
Hi Alby,

I see that Toyota now have a shorter tray option available. I’m fairly comfortable with our set-up, ensuring load is as far forward as possible.

Customising is never-ending!

Cheers, Baz – The Landy
FollowupID: 839797

Follow Up By: AlbyNSW - Monday, May 18, 2015 at 08:30

Monday, May 18, 2015 at 08:30
I havn't seen that Baz, will look out for them
I made my tray only 1700 long to keep the weight forward
You are right about customizing being a never ending process and expensive one

Glad I am happy with my one and only wife as changing them makes vehicle mods look cheap lol
FollowupID: 839801

Reply By: vk1dx - Friday, May 15, 2015 at 15:33

Friday, May 15, 2015 at 15:33
Thanks Baz - Interesting report.

We do all our trips solo now and they aren't what one would call safe and easy drives. We try to stay off the bitumen and "made" roads as much as we can. Love the remote areas. The Madigan solo soon. Safety, reliability and recovery being the over riding selection criteria. I like the policy that if you don't need it then don't take it. However at 70 and (won't say my wife's age) we do like the softer thicker mattress etc. And especially the 2nd smaller fridge/freezer which carries the ice cream. Bugger it - why rough it at our stage in life.

Our trip so far
The car is a "heavy" Toyota 100 series 2005 GXL 4.2TD IFS. And without an approved kit it has been an interesting job. We are going to 3700 Kg. Just a tad under the magic 3780 figure.

Until we sat down with the engineers who did some investigations of what we had done, or importantly not done, to the car plus a heap full of magical mathematics, (note not american maths) I believed that it was an unachievable goal to be "legal" at something less than the cost of an aircraft carrier.

Our previous mods included:
1. A couple of simple safety kits (lower wishbone and torsion bar mount strengthening), 2. rear spring upgrade by one stage and
3. Bilstein shock absorbers.

What also helped was no lift or any other work on the car. The engineers had a known, stable and strong platform to start with. They were pleasantly happy that we hadn't lifted it.

The following tasks were identified;
1. the installation of some stability air bags in the rear springs - Done,
2. get a new tare weight certificate - Done,
3. the removal of the third row seat belts - Done,
4. pass a stability and lane changing test drive - track booked for 5th June, and
5. engineers prepare RTA documentation.

Then off to the RTA. Maybe a pit inspection, but it's not obligatory. It would be fine for the pit inspection.

The hardest bit was getting all but 10 litres of fuel out of the car for the weighbridge tare ticket. that's 200 litres. Could you store 200 litres at home.

Relief in sight.

AnswerID: 553796

Follow Up By: The Landy - Monday, May 18, 2015 at 08:01

Monday, May 18, 2015 at 08:01

Thanks for the insight, and I look forward to reading about your upcoming trip...

Cheers, Baz
FollowupID: 839798

Reply By: axle - Friday, May 15, 2015 at 15:39

Friday, May 15, 2015 at 15:39
Hi Baz,...Hmmm, Just how good are the 130 Deefers in standard form with their load carrying capacitys........LOL.

Cheers Axle.
AnswerID: 553797

Follow Up By: The Landy - Friday, May 15, 2015 at 21:27

Friday, May 15, 2015 at 21:27
Oh strewth, there I was enjoying a beer and you had to bring that matter up!

Yes, good load capacity,

Cheers, Baz

FollowupID: 839692

Reply By: Rick (S.A.) - Friday, May 15, 2015 at 18:25

Friday, May 15, 2015 at 18:25
Baz, a very timely post from you.

Just a few days ago I posted this on the 4WD Action forum. It's interesting that tyres & fridges & GPS posts get wayyyy more reads than a post like yours or mine.......


Weight of your 4WD
I wonder how many of us have a good understanding on what our loaded up rigs weigh?

If over Gross Vehicle Mass (GVM) the potential exists to:

(1) Break stuff, as the 4WD is not engineered to take the extra weight. You may only find this out when remote touring, for example, when roads & conditions stress everything beyond your normal scenarios. I know, ol' mate around the corner has driven heavily laden 4WD's for yonks and he's never had an problem. But can you honestly say you are not going to be either overweight or drive repeat hours - or both - in extreme conditions?

(2) Lose huge sums of money. If perchance the 4WD is involved in an insurance claim, my understanding is that, in theory, an insurer could reject a claim if over GVM. No matter if your fourby is worth $ 15 K or $ 95 K it could hurt to lose that amount in event of no insurance cover.

(3) Have significant and costly delays while repairs are being made. This cost could be exaggerated when in a remote area. For example, you break a suspension mount at Cape York or on the Gunbarrel Highway & you have to call for professional help. It could be from hours to days away. I'd caution here against the NIMBY syndrome - just look at the business local mechanics do at Birdsville and Mt Dare.

In general terms, wagons have a payload of 450-600 kgs; while dual cabs have payloads of 750-1,000 kg. A vast difference, indeed (don't have data on single cab utes, unfortunately, but I reckon they are of 1,000 kg order).

If you have a wagon and you have 4 people + 20 L water (enough for one day) + 20 kg personal gear & sleeping stuff each + a 40 L fridge & contents + some tucker & some cooking equipment, you're likely at GVM. Add any of these: bullbar, sidesteps, roofrack, recovery gear, winch, tools, compressor, 2nd battery, extra fuel, tables & chairs, tent, trailer or whatever, and you'll be well over GVM.

By way of example, I drive a 2011 build Mazda BT 50 auto dual cab. Currently it does not have a bull bar, but has ARB side steps. With a custom ally canopy + roofrack, 2nd battery, twin 1000mm drawers (one drawer loaded with of 45 kg of recovery gear,tools & compressor), full of fuel with me on board, it weighs 2730 kg.
If I add a 50 L fridge, wine & beer, 2 x swags & stretchers, 2 x chairs, table, pots'n'pans, 30 L water, food, one passenger, and two personal bags, it weighs 3,026 kg.
Take a second spare, another passenger, swag & bag, some extra fuel & water, etc - PHEW! - I'm over GVM!

I appreciate vehicle manufacturers quote payloads and towable loads which seem high. But how will those vehicles cope when being operated for hours/km's/days/weeks at the extreme of design & build strength?

If like me you have pushed the envelope, you'll find out that in the end, everything breaks or cracks. I'm talking serious stuff here, from shocks to chassis to axles to roofracks. Brand has no part to play - current Toyotas, Nissans and Mazda's all will fail. And that's only in my limited experience.

Food for thought, eh?


That's the post - it has had about 9 replies, a tiny response relative to some other threads, which leads me to reckon its not of concern to most vehicle operators.

AnswerID: 553806

Follow Up By: vk1dx - Saturday, May 16, 2015 at 08:44

Saturday, May 16, 2015 at 08:44
It sure adds up Rick. But isn't it more like a "head in the sand" thing. We were over on many occasions but all that will soon be fixed. Thank God.

FollowupID: 839704

Follow Up By: The Landy - Monday, May 18, 2015 at 08:14

Monday, May 18, 2015 at 08:14
Hi Rick

It is a very important topic and as you indicated often overlooked in the discussion of other touring requirements.

Perhaps I will sound quite anal-retentive; however I have a load chart that records the basic empty weight of the vehicle and items that are loaded. The process is actually quite straight forward as the gear carried is fairly static. After that load is determined I can consider the fuel capacity that I can put in.

So at any given time I can accurately determine the vehicle weight.

As part of my pilot training many years ago, loading was always critical to the flight planning process – I don’t see this any differently. Importantly, if I load the vehicle in line with the OEM, and in my case the engineer approved modifications, I can be reasonably sure the vehicle will perform as designed.

Now we have a fairly large canopy on the back that provides an opportunity to fill it, however we only take what is required and there is always plenty of “empty space”. I think the mistake often made is to fill every empty space with something when touring.

And this is the added advantage of weighting everything that goes into the vehicle, it makes you stand there and ask the question “do I need this”.

The main point I am highlighting of course is to ensure that any modification undertaken is not going to impact something else down the track. And whilst not a slight at Lovell’s, it is important to recognise that its approval for GVM upgrades on this vehicle to 3,900kg can be a limiting factor on other work undertaken in the future.

For those thinking GVM and GVM upgrades, always (always) consider the axle loading.

Thanks for taking the time to highlight your thoughts and insight!



FollowupID: 839799

Reply By: Notso - Friday, May 15, 2015 at 19:26

Friday, May 15, 2015 at 19:26
It's a bit like buying a bigger garden shed. You'll always fill it up and want more so you may as well stay with the little shed and save a heap of brass.
AnswerID: 553808

Reply By: 671 - Friday, May 15, 2015 at 21:34

Friday, May 15, 2015 at 21:34
Do GVM upgrades come with an upgraded chassis or is it just springs? The chassis should be the first thing that gets upgraded followed by everything else.



I don't know about the Defender's carrying capacity but, according to Landrover, its towing capacity comes down from 3500 kg to 1500kg off road. I would not be surprised if carrying is much the came.
AnswerID: 553812

Follow Up By: vk1dx - Saturday, May 16, 2015 at 09:16

Saturday, May 16, 2015 at 09:16
Thanks 671.

An interesting article and it reminds me of what we were taught when getting a licence. I also got the same story from Dave.

To answer your question the only "chassis" type of works required for our 100 series upgrade were lower wishbone arm and torsion bar strengthening kits. The spring change and air bags were for added shock and stability management roles.

FollowupID: 839706

Follow Up By: 671 - Saturday, May 16, 2015 at 14:43

Saturday, May 16, 2015 at 14:43
That article (and the editorial that mentions reducing loads in off road conditions) should be compulsory reading for anyone going bush, particularly with a cab/chassis ute.

I don't recall ever hearing anything about chassis damage on a 100 series but I can't say the same about the rear axle housing. It is under a huge amount of stress with a full load combined with a little speed on rough roads.

It is a bit like weight lifting. A 120 kg man could lift a 120 kg bar above his head and the bar will bend down a little at the ends and curve up slightly in the middle. When he drops it, it will hit the floor with a force far in excess of 120 kg. If he was to place his hands on the bar in the same position and do a hand stand on it, the bar would bend down in the middle by the same amount it did when he had it above his head.

A live rear axle in a car is the same as a weight lifter's bar. It has springs sitting on it out near the ends just like the lifter's hands. There will be way over two tons being slammed down on to it when a fully loaded or GVM upgraded Cruiser falls when its wheels drop into a depression on the road. The centre of the housing will bend down ever so slightly increasing the tension across the bottom of the housing. If it happens enough times, cracks can and do eventually appear.

This is just one of the reasons why the maximum carrying and towing capacities of cars are the maximum possible in good sealed highway conditions. Both the speed and load should be reduced as conditions deteriorate.

If car owners did that, the bush repair workshops would be out of business.
FollowupID: 839711

Follow Up By: The Landy - Monday, May 18, 2015 at 08:21

Monday, May 18, 2015 at 08:21

An important point and consideration in any vehicle modification is to ensure it compliments everything else.

In terms of Defender's, at least the 130, there was no off-road load limitation. Of course, it should always fall to the operator that speed and handling is adjusted to take account of the loading of the vehicle.

Cheers Baz - The Landy

FollowupID: 839800

Follow Up By: Bob Y. - Qld - Monday, May 18, 2015 at 16:50

Monday, May 18, 2015 at 16:50
"..........chassis damage on a 100 series......."

I had to do a double-take, 671, but saw a 100 series, modified to a dual cab, with an alloy mesh canopy, in Longreach last year.

It was towing a hard top camper trailer, and the chassis bend was almost as bad as the many photos we've all seen on the mid-sized Utes. Didn't get a photo as I was in shock! :-)


Seen it all, Done it all.
Can't remember most of it.

Lifetime Member
My Profile  My Blog  My Position  Send Message

FollowupID: 839825

Follow Up By: The Landy - Tuesday, May 19, 2015 at 11:13

Tuesday, May 19, 2015 at 11:13

Had a good read of the article and interesting to note the very first picture was of a vehicle with leaf springs and an airbag – the making of a potential problem in the first instance…

What the article highlights is the importance of engaging a specialist suspension workshop and potentially an engineer when making adjustments to suspension. In the case of a GVM upgrade an engineer will be required to sign it off.

In terms of diff housing and axles, it is important that vehicles are loaded with reference to the axle ratings of the vehicle and I suspect many overlook this. Manufacturers do testing to ensure rated loads do not compromise the parts and workings of the vehicle. Does a chassis need reinforcing, usually not, but a good question to ask when making these sort of changes to a vehicle.

But importantly, once off-road it is key to ensure the vehicle is operated taking all factors into account, and this may mean slower if heavier.

Mind you, some cab chassis Utes will perform better than others, hence our choice of vehicle.

It is worth noting that the rear axle is not always the issue. If you put a steel bull-bar with a winch and a couple of average sized blokes in the front seats of many, including a Hilux you’ll be close to, or over the front axle weight limitation.

All food for thought…

Cheers, Baz – The Landy
FollowupID: 839863

Follow Up By: Jackolux - Tuesday, May 19, 2015 at 13:39

Tuesday, May 19, 2015 at 13:39
I have just sold a 06 Hilux D4D , unless Toyota changed the specs , I don't think they have , if you have a Winch Bar , winch , extra battery under the bonnet even with just the Driver you will be over the Max front axle loading .

I bought a new Dmax and got a GVM upgrade before rego , 2950kg increased to 3220kg , if I was to load it to Max GVM the extra 270kg is the max rating of the rear axle .
FollowupID: 839866

Follow Up By: vk1dx - Tuesday, May 19, 2015 at 17:20

Tuesday, May 19, 2015 at 17:20
Weighed our car again today. Winch, steel front and rear bars and steel sidesteps, 90 litres fuel, extra tank, third battery, steel framed drawer system (wont come loose if car upturned). 3220 Kg. !!!!! No fridges or any camping stuff. No clothes or tentage. No fridges (2). No roof rack and roof top tent. Small weight additions but we have had a few suspension reinforcing plates welded on (tortion bar mount and wishbone arms)

In a word. Ouch and thanks God we will be safe and legal next week. The engineers calculations have shown that the suspension will be fine.

If it passes the driving tests and we go to 3700 Kg GVM.
FollowupID: 839875

Sponsored Links

Popular Products (9)