Tow Ball Download weight confusion with state legal

[apilko]

Hi all - I'm new to the group but this issues driving me crazy as there appears too be a lot of conflicting information depending on which view you take. It's a complicated long note so please bear with me...

Spoke to a guy that owns a weigh bridge business and he explained the issues...
Some (not all) of the critical weights to do with towing - GVW which is the max allowed weight of the vehicle (My D4 - 3240kg), The GCM which is the max the car and van can weigh (My D4 - 6,740kg), The tow capacity (3,500kg) and the Tow Ball Download (in this case 280kg). Now the D4 can take up to 350kg of TBD BUT to allow for this you use the 'detachable drawbar receiver' and the manual says that if you do this then you have to reduce the overall GVW by 200kg (tried to attach pic from manual).

BUT if you minus the 200kg off the GVW then that only leaves you 3,040kg - then if you minus the weight of the car with fuel and accessories (2702kg) you end up with a remaining payload of 338kg - NOW 338kg payload is final for passengers and luggage, BUT if that payload has to account for the 290kg of TBD then you're only left with 48kg - not even enough for a driver!

OK that's the numbers now here's the legal stuff. What this guy told me is this - LR and lots of other manufacturers build cars that can take plenty of weight but then the GVW is underquoted on the GVW cert. For example in the case of LR the car has a 1 ton payload but what they do is call it a 750kg payload and then say that you can have the TBD weight as extra (ie not have to include it in calculations) - GREAT - EXECPT NOT GREAT BECAUSE...The registries in VIC and NSW (don't know about the others) have no interest in looking at or approving individual vehicle manuals with particular allowances - instead they simply just take the GVW printed at the time of certification THEREFORE trying to put any decent van weight legally on a Disco is legally very difficult.

He says that this is happening with Nissan, Mitsubishi to name a few. He says that if you're buying a new car you can get them to reassess the GVW before registration and get the manufacturers weights included properly but once registered you can't get it changed without a GVW upgrade. So basically he suggests two options
1) Talk to LR and somehow get them to rectify the vehicle (practically impossible).
2) Get a GVW upgrade - if I get a GVW upgrade won't it mess with the air suspension?

Phew - what a headache this all is - This guy says that 8/10 people he weighs for certification fail because if this kind of error. Have you ever heard of this situation? Is there anyone out there with a Disco that tows a big van (TBD above 250kg) that has a weighbridge cert? Basically if you have an accident and they do the weight calculations then you're not insured. Any advice or hot line to LR or access to GVW upgrade people welcome.

[apilko]

Land Rover tow ball download weight issues…

Spoke to a guy that owns a weigh bridge business and he explained it all to me but still some issues - try and stay with me here...
Here are the relevant critical weights - GVW which is the max allowed weight of the vehicle (My D4 - 3240kg), The GCM which is the max the car and van can weigh (My D4 - 6,740kg), The tow capacity (3,500kg) and the Tow Ball Download (in this case 280kg).


Now the D4 can take up to 350kg of TBD BUT to allow for this you use the 'detachable drawbar receiver' and the manual says that if you do this then you have to reduce the overall GVW by 200kg (see pic). BUT if you minus the 200kg off the GVW then that only leaves you 3,040kg - then if you minus the weight of the car with fuel and accessories (2702kg) you end up with a remaining payload of 338kg - NOW 338kg payload is final for passengers and luggage, BUT if that payload has to account for the 290kg of TBD then you're only left with 48kg - not even enough for a driver.


OK that's the numbers now here's the legal ****. What this guy told me is this - LR and lots of other manufacturers build cars that can take plenty of weight but then the GVW is underquoted on the GVW cert. For example in the case of LR the car has a 1 ton payload but what they do is call it a 750kg payload and then say that you can have the TBD weight as extra (ie not have to include it in calculations) - GREAT - EXECPT NOT GREAT BECAUSE...The registries in VIC and NSW (don't know about the others) have no interest in looking at or approving individual vehicle manuals with particular allowances - instead they simply just take the GVW printed at the time of certification THEREFORE trying to put any decent van weight legally on a Disco is legally impossible without modifications.


He says that this is happening with Nissan, Mitsubishi to name a few. He says that if you're buying a new car you can get them to reassess the GVW before registration and get the manufacturers weights included properly but once registered you can't get it changed without a GVW upgrade.


So basically he suggests two options 1) Talk to LR and somehow get them to rectify the vehicle (practically impossible). 2) Get a GVW upgrade - if I get a GVW upgrade won't if mess with the air suspension?


Phew - what a lheadache this all is - This guy says that 8/10 people he weighs for certification fail because if this kind of error. Have you ever heard of this situation? Do you know anyone with a Disco that tows a big van that has a weighbridge cert?


I really need some help with this as no one seems to want to give me a straight answer except the weighbridge guy who sounds very experienced in this space - but if what he says is true then no one with a Disco would be legally able to tow a bug caravan - which surely can’t be right.

[p38arover]

A few more paragraph breaks would make it much easier to read your post. I gave up.

However, you might want to look up this YouTube video by John Cadogen which summarises it quite well.

Complete guide to heavy towing (GVM, GCM & ATM explained)

[101RRS]

You are looking at the manual - a UK publication. If it was a D3 or RRS I would say have you looked at the Australian Supplement which is a small supplementary publication which changes the ball weight up to a straight 350kg.

Does the D4 have an Australian supplement? I dont know about D4s so check this out.

Garry

[101RRS]

Why post the same question twice?

[josh.huber]

My understanding with a D4 was that the to ball download of 200kg didn't have to be added to the car. It was already allocated.. So.. if I'm right and I'm probably not. if your ball weighs 260kg you only need to add 60kg to the car. I'm sure it said it in the manual. I'll check tonight. I do know that from previous conversations with the book out the D4 outperforms most vehicles with something chasing it

[rocket rod]

Your right it is very complicated. For a start I would probably engage a mobile caravan weighing company rather than a generic weigh bridge. Although your guy's advise is welcome this will give you a far better understanding of what weight is where and how to rectify it. Also, cross GVM upgrade off your list as I don't believe this is possible with your D4 and this maybe law soon RV DAILY | GCM Upgrades - New Draft Federal Code Leaked (https://rvdaily.com.au/gcm-upgrades-new-draft-federal-code-leaked/)

[p38arover]

Thanks for adding paragraph breaks - much more betterer (as my neighbour would say).


Why post the same question twice?

I've merged the two posts. I haven't checked to see if they are the same.

[Narangga]

Thanks for adding paragraph breaks - much more betterer (as my neighbour would say).



I thought I had patented that? [bighmmm]

[Mungus]

First paragraph correct, second paragraph correct at face value (see below), so if you take your roughly 50kgs of accessories off (I’d guess second battery) you’ll be able to drive it. 🤪 Sorry couldn’t help myself.
Not sure where you got the 1t from in the third paragraph. I have never seen this documented.

Seriously though, there are many threads on this topic and not one of them actually gets to a concise final result and are even more confusing if LRA are asked to clarify.

Regarding your second paragraph. I agree to some extent (although still confusing) with some comments in other threads that 150kg of your 290kg (or max 350TBD) is included in your original stock GVW, so you would only consider in your case adding 140kg of your 290kg to your GVW, but as also mentioned in those other threads the road side weighing officers wouldn’t take that into consideration, let alone be able to understand Land Rovers complicated calculations. Would they have the owners manual to calculate all this or would they simply look at your compliance plates and check GVW, Axle Loads and Hitch.

Another point to consider is this (if you have one), are the Mitch Hitch or other ADR compliant Australian made hitches? Land Rover “approved”? I’d say not and all in the Manual refers to LR’s two types of OEM hitches only, with a warning to only use LR approved.

Interesting in the manual extract you uploaded, top of second column, that in the EU, GVW can be increased by 100kgs so long as you speed limit to 100km/r. Maybe LRA should adopt the same here in Aus.

I got myself in a hissy fit over all these weights and then after researching found that in reality all other manufacturers have the same and/or other issues, even upgraded GVM Toyota’s, which will be a topic I want to discuss in another thread, once I have all the facts and figures.

Load her up to 3240, 6740 and enjoy your travels. Just don’t have an accident.

[Mungus]

An interesting twist from LR Owner Information for late model Defenders and Range Rovers. It may be a sliding scale?
¹ For every pound above 331 lbs (150 kg) added to the trailer tongue weight, the same weight must be removed from the vehicle's payload. Make sure that the GVW, the GTW, and the maximum rear axle weight limits are not exceeded when applying the trailer tongue weight. If required, reduce the weight of the vehicle's payload.

[Blknight.aus]

BUT if you minus the 200kg off the GVW then that only leaves you 3,040kg - then if you minus the weight of the car with fuel and accessories (2702kg) you end up with a remaining payload of 338kg - NOW 338kg payload is final for passengers and luggage, BUT if that payload has to account for the 290kg of TBD then you're only left with 48kg - not even enough for a driver!


Thats youre mistake right there..

the 200kg comes out of the GVM, if you then take it out of the payload you've removed the weight twice.

and even if it was, as its a landrover that 48kg is more than enough for the driver. Unless they've changed it every landrover manual I've ever read through includes an allowance for the driver, tank of fuel, spare tyre and a sundry of other things, this is why if you ever weigh bridge it you'll probably find that you can get more into a 750KG net rated landrover than you can a 1T anything else....

there was a stage where a certain company was advertising 1t utes, problem was the payload did not include, the tray, a tank of fuel, the spare tyre, the driver or anything else over the very basic pov pack, hell if you bought it in the auto version it wasnt even a true 1T vehicle as a bare cab/chassis.

[Drafrete]

Hi,

It is a challenging topic and one that the manual and supplements and published specifications for the D4 don’t really make crystal clear. I looked into this too, to try to make sure that if I loaded the D4 and Van that it would be within limits. What I came to might be some help.

It seems to me that the critical limit when considering towing with the D4 is not so much the GVM as the rear axle capacity. The maximum rear axle capacity for the D4 is 1855kg. When considering the mass on the rear axle the tow ball load must be considered. It is important to realise that because the tow ball hangs off the back, the load on the rear axle to be included is greater than the actual weight. Typically, the load share carried by the rear axle is 1.5 times the weight of the ball (it can vary).

If you have 280kg of ball weight, then the extra load carried by the rear axle is probably 420kg. If you have a lightly laden D4, with some fuel and a couple of people, let’s say that is 2,800kg. Add 420kg and you end up with about 1820kg on the rear axle. You can’t really go much more in the back (35kg) without over-loading the rear axle capacity.

It seems to me that the numbers that the OP came up with look about right. It is hard not to overload the rear axle, depending on how much extra stuff is on/in the car with a large van. The LR supplement suggests that a target tow ball mass of about 7% is the suggested minimum. I agree having looked at the limits on the rear axle. Lighter ball load is better. And in light of the GVM reduction that the OP noted for >250kg ball weight, a ball weight of 250kg would seem to be a good target. Oh and 7% of 3,500kg is 245kg.

Just one of many views on this.

[350RRC]

And no one can explain or identify the source of the science behind '10%' rule that leads people to putting 350kgs of weight on the ball to drag something along at 90 degrees to the 'force'.

I have a genuine LR plated RRC towbar, max ball weight 120kg, max tow weight 4,000kg.

DL

[350RRC]

And no one can explain or identify the source of the science behind '10%' rule that leads people to putting 350kgs of weight on the ball to drag something along at 90 degrees to the 'force'.

I have a genuine LR plated RRC towbar, max ball weight 120kg, max tow weight 4,000kg.

DL

[Tombie]

And no one can explain or identify the source of the science behind '10%' rule that leads people to putting 350kgs of weight on the ball to drag something along at 90 degrees to the 'force'.

I have a genuine LR plated RRC towbar, max ball weight 120kg, max tow weight 4,000kg.

DL

And when one of the mobs out there did a random weigh in, they found all those who claimed to be running at 10% were often closer to 5-7%.

Overseas 5-7% is the norm, just another Aussie thing I guess.

[PeterJ]

Perhaps it's a case of making it all a lot harder than it is, try this.
Load the van and car as you would if you were setting off on a trip, the whole nine yards.
Find a public weigh bridge or private one that is weighs and measures certified.
Roll onto the weigh bridge with the van attached and get the operator to record front axle mass, then whole vehicle, ( you can calculate rear axle mass from this), then car and van combined (this gives you GCM) and finally van axle group, and you have GTM. (Gross Trailer Mass - the load on the van axles not including tow ball mass)
Then check these values against the vehicle and caravan specifications and adjust as necessary.
At the end of the day this is what is important from your safety, road legal and insurance perspective.
Peter

[Andrew Halliday]

Its a complicated topic. My take on it is to focus on 3 things. Tow ball weight, trailer weight and total train weight.

Tow ball weight is highly variable. For example:

I have a D4 and a rather large boat. On the weigh bridge the boat with 400L of fuel and 100L of water and all the gear weighs 3160kg. Obviously its rare I would tow it around with that much fuel in it.
When I first got the boat it towed terribly - bouncing around and it felt like it was lifting the back of the car. So I bought a tow ball weight measuring device and the TBW was only 60kg! I made quite a few adjustments to where the boat was positioned on the trailer and where all the weight was and increased the TBW to 160kg. This tows very nicely now. I checked this both with the gadget and also at the weigh bridge:
1 boat attached to car both on bridge = 5830kg
2. Boat attached to car but car off the bridge 3000kg
3. Boat unattached to car and boat on bridge 3160kg.

So my rear axel weight is fine, and my total train weight is fine.

So I would take your own measurements and buy a simple measuring device - you might be surprised.

[gruntfuttock]

Four towing weight examples - explained! - YouTube (https://youtu.be/YPQDWo3YEwI)

[taffy]

I use one of the reich caravan load scales to measure all the axle loads.
It's a bit fiddly .but you drive over the scales with each wheel. Then you have all your axle loads. You can do your ball weight prior to connecting up.

[IndusD4]

Overseas 5-7% is the norm, just another Aussie thing I guess.

Maybe this is due to caravan design. European vans tend to have the wheels in the centre of the van, where Australian built vans they tend to be further back. Wouldn't that cause more of the weight to be on the tow ball?

Ron

[Pedro_The_Swift]

Caravan manufacturers in OZ just build it then put the suspension subframe wherever ten percent is. No time to overthink it.
(Having a ceramic toilet is FAR more important than road manners afterall... :bat: )

There is a 20 month waiting list for new Titanium caravans, 12months is the new normal.

[Tombie]

Maybe this is due to caravan design. European vans tend to have the wheels in the centre of the van, where Australian built vans they tend to be further back. Wouldn't that cause more of the weight to be on the tow ball?

Ron

That’s just it.

Yet when weighed a heap still ran at 6-7%

Many van builders are rogue, will build anything rather than risk losing a sale by denying a customers request.

Then of course we have those customers who insist everything be like home and fit ridiculous gear and push maximum weight and want a borderline tow vehicle.

[StewG]

As Drafrete said earlier, check your axle loadings are correct and the GVM and GCM will probably be ok. It is very easy to overload the rear axle, even with a 2.5 T trailer (approx. 10% TBD) and a full boot even without exceeding the GVM or GCM. Do your best guess on weight distribution and then weigh each axle to stay safe and legal.

[haydent]

Great thread, In case it hasnt been mentioned, Tow Ball Weight x 1.5 = appx weight on rear axle due to leverage


Hi,
The maximum rear axle capacity for the D4 is 1855kg.

D4
5 Seater 1855kg
7 Seater 1885kg

D5
5 Seater 1775kg
7 Seater 1900kg

[gavinwibrow]

Great thread, In case it hasnt been mentioned, Tow Ball Weight x 1.5 = appx weight on rear axle due to leverage



D4
5 Seater 1855kg
7 Seater 1885kg

D5
5 Seater 1775kg
7 Seater 1900kg


So, if the towball weight is 200, you are saying the additional weight on the rear axle is in the order of 300?

[discomatt69]

So, if the towball weight is 200, you are saying the additional weight on the rear axle is in the order of 300?
Last time I weighed mine properly with the car loaded and van hitched, and seperate, front and rear axle the full weight of the drawbar is on the ball , where the extra 100 kg. comes from is the front axle looses weight and it’s put onto the rear.
i was very surprised at this and weighed it all again just to be sure I hadn’t done the process incorrectly some how.
I thought that because of the self levelling suspension it wouldn’t transfer so much of the weight, I was wrong and it does, that was with a ball weight of 280kg. which was also the o much for the van which weighs 2500kg
i have reloaded the back of the car and the van to improve the distribution and it did make it more stable , not that stability was a issue due to the brilliance of the car but now it’s even better
there is no calculations to do, no adding or taking weight off, rear axel limit is a set number and that’s the one that gets exceeded very quickly

[haydent]

i just recently found out from some youtube video examples that self levelling suspension actually make it worse, as when the air bags inflate to level it it actually puts more weight on the rear axle than with the sag ... i also found a weight distribution hitch work to move about 80kg off the rear axle

[DiscoJeffster]

i just recently found out from some youtube video examples that self levelling suspension actually make it worse, as when the air bags inflate to level it it actually puts more weight on the rear axle than with the sag ... i also found a weight distribution hitch work to move about 80kg off the rear axle

Weight distribution hitches are a no no on the Discos. I'm sure it says it in the manual somewhere

[discomatt69]

Weight distribution hitches are a no no on the Discos. I'm sure it says it in the manual somewhere
I think that is to allow for the moron factor and people putting way to much pressure on them, Jeeps with the same air suspension set up have no issues using a WDH

[haydent]

Weight distribution hitches are a no no on the Discos. I'm sure it says it in the manual somewhere

I dont think it is mentioned anywhere, and its just a old wives tale that you cant use them. There is nothing special about them that the suspension would even experience or have to interact with, all it does is change the load experienced by the axles by making a stiffer joint at the hitch.

no different to just having a heavier or lighter tow ball weight through normal means

[Saitch]

I think that is to allow for the moron factor and people putting way to much pressure on them, Jeeps with the same air suspension set up have no issues using a WDH

I remember reading an investigative report by a large, Australian, towing company, into caravan accidents, which basically stated that " If a WDH is required, then: 1) The tow vehicle is unsuitable. 2) The van is unsuitable. 3) The cargo distribution is incorrect. ".

[haydent]

I remember reading an investigative report by a large, Australian, towing company, into caravan accidents, which basically stated that " If a WDH is required, then: 1) The tow vehicle is unsuitable. 2) The van is unsuitable. 3) The cargo distribution is incorrect. ".

this is an idealistic take, id prefer to not use one simply from the point of view of it being less gear and process to hook up.

but from a functionality point of view, they do actually work and are very popular and i see them on every brand of car.

a car will inevitably sag with added weight on the rear, and reducing this sag helps with handling and axle loads.

i think its also a problem that Australian caravan manufacturers seem to build very front heavy vans compared to their european counterparts.

they also smooth the ride by stiffening up the joint where the hitch is, which normally needs to pivot, but can have benefit to resistance of such in the up and down direction compared with the side to side.

smoothing out bounciness is a big safety plus

sure they can be used in situations where something else should be changed, and they might be over represented in accidents, as these are people that might be near their limits, but there is a huge range of legal towball weight allowance for any car and van combo, this is just another way to let you adjust it, while having added benefits as mentioned

[DieselLSE]

I dont think it is mentioned anywhere, and its just a old wives tale that you cant use them. There is nothing special about them that the suspension would even experience or have to interact with, all it does is change the load experienced by the axles by making a stiffer joint at the hitch.

no different to just having a heavier or lighter tow ball weight through normal means

Nup. Right there in the handbook. Page 190: An equalising or other form of weight distributing hitch should not be used with your vehicle.

194215

[haydent]

ah thanks for that, i stand corrected, i was searching for different words than what they used. pity there's not more detail there as to why, if they think its just not necessary or something else

[DieselLSE]

ah thanks for that, i stand corrected, i was searching for different words than what they used. pity there's not more detail there as to why, if they think its just not necessary or something else
No probs. I've been rummaging through the workshop manual, but it doesn't rate a mention.

[Tombie]

ah thanks for that, i stand corrected, i was searching for different words than what they used. pity there's not more detail there as to why, if they think its just not necessary or something else

The Why is that the suspension will continuously fight the WDH causing issues rather than solving them.

The vehicle measures load, think inline with how it knows it's grounded offroad and goes to super extended - it's the load measured inside the bag (pressure) and keeps trying to return to spec.

WDH are a band-aid. The added stresses on the frame and hitch point are quite crazy.

As another mentioned - a well set up combination won't need them. Our 24? van certainly doesn't.

[discomatt69]

I certainly don't need a weight distribution hitch but what do need is a GVM upgrade because the car handles exceptionally well, tows fantastically and feels safe and stable along with good servicing and maintenance there are no issues other than the legality of numbers?

[haydent]

The Why is that the suspension will continuously fight the WDH causing issues rather than solving them.

The vehicle measures load, think inline with how it knows it's grounded offroad and goes to super extended - it's the load measured inside the bag (pressure) and keeps trying to return to spec.

WDH are a band-aid. The added stresses on the frame and hitch point are quite crazy.

As another mentioned - a well set up combination won't need them. Our 24? van certainly doesn't.

the vehicle does not measure load at all, id thought it wouldnt be hard for it to be able too with a few more pressure sensors, it could give you axle load numbers by measuring the air bag pressures.

(it only has one pressure sensor to measure the reservoir pressure)

it works out the extended mode from the height sensors, and if it cant lower itself

the WDH hitch itself balances out the force from the smaller upforce of the bars and the greater trailer downforce , the result of this is then experienced as less downforce on the receiver. the bars also put pressure on the a frame

the only reason im using one is to move weight off the rear axle, you wouldnt think you needed one otherwise with self levelling suspension as it will hide the overloading of the rear end

The Effect of 4 Corner Auto Leveling on a Weight Distribution System

https://www.youtube.com/watch?v=mj2oqAiltsk


I certainly don't need a weight distribution hitch but what do need is a GVM upgrade because the car handles exceptionally well, tows fantastically and feels safe and stable along with good servicing and maintenance there are no issues other than the legality of numbers?

i think youll find you will go over your rear axle limit before the gvm one (the opposite problem of a 200 series lc)

[101RRS]

I dont think it is mentioned anywhere,

Its in my Hand book.

[haydent]

yes, i was corrected here Tow Ball Download weight confusion with state legal (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/286049-tow-ball-download-weight-confusion-state-legal-post3250680.html#post3250680)

[Tombie]

All this clowning is really irrelevant...

Shove a WDH on - have an accident - watch your insurer walk away doing this... [bigrolf]

[veebs]

I appreciate it isn't always as simple as this, however I'd suggest if you're at the point where a WDH makes the difference between being within axle weight limits or not, you need to pack less, tow less, or invest in a more appropriate tow vehicle for your needs...

[haydent]

There is some truth in this potentially but you might be surprised that i measured a 80kg reduction in rear axle weight which is about a 20% reduction in the load applied by a 260kg ish towball weight (360kg axle load)

[discomatt69]

There is some truth in this potentially but you might be surprised that i measured a 80kg reduction in rear axle weight which is about a 20% reduction in the load applied by a 260kg ish towball weight (360kg axle load)
Which going by the video you posted can cause safety issues?..

[Tombie]

There is some truth in this potentially but you might be surprised that i measured a 80kg reduction in rear axle weight which is about a 20% reduction in the load applied by a 260kg ish towball weight (360kg axle load)

Move the van height relative to the tow ball can do exactly the same.

[haydent]

Which going by the video you posted can cause safety issues?..

sorry i missed that bit ? what is the safety issue ?

[Redback]

I did't have the manual at hand after reading this, but, I thought(from memory) that the D4 MAX tow ball weight was 250kg, to find out it's 350kg,well, for me that's insane, even 200kg:Thump:

The average caravan manufacturer make dangerous caravans, the vans are too tall and unstable, IMHO:whistling: