Tow ball weight limit with WDH

10-15 % is better under 10% is not advisable.
The usual way to determine your towball weight is look at your compliance plate It has ATM and GTM

Deduct GTM from ATM to get the approximate ball weight.

HOWEVER it depends on how you load the van and itis best to load everything up and go to a weigh bridge to get an accurate reading.

Then go home and chuck out all what you dont really need to get it legal LOL

I think you are over complicating things really
I would worry if you had a 2200kg van and only 170kg on the ball as it could be seriously unstable at any decent speed.

What vehicle are you towing with and what model van as giving advice on unknowns is like trying to do brain surgery over the phone with a blindfold on. If you get what I mean.

The more info the better answers you will get.

You will be far better with a WDH under any circumstance than without one,
However it will not help if you van is unstable due to to little ball weight

Ball weight = ATM - GTM is not a reliable way to think. The ball weight of a van varies considerably and depends upon how your van is loaded. You may achieve a ball weight as calculated above if you can manage to load a van to its ATM and GTM.

The only way you can determine the ball weight of a van at a particular time is to weigh it then and there. Next time you load the van it will probably have a different ball weight (unless you can load it exactly the same.)

The 10% rule was developed back in the days when the average length of van was around 16' and 18' was considered big. There are people who have worked in the automotive field and studied the dynamics of vehicles in motion that argue that longer vans require a heavier ball weight.

This 10% of course only applies to Australian built vans. Australian builders do not make an effort to concentrate the weight in the centre of the van. They build front and rear kitchens, install heavy bumper bars with all sorts of heavy items on them and the front boots are way larger than the European ones. That is why the ball weight rule for European vans is 5 - 7%. You never see front or rear kitchens, no bumper bars, small or no water tanks and the spare wheel is mounted under the van just behind the axle.

The greater the inertia at the ends of the vans, the greater the ball weight that is necessary to control the van. You can increase the inertia by increasing the end weight or lengthening the van.

Totally agree Thats why I said load it up and weigh it at a weigh bridge.

Only sensible accurate way.

The ones who add tool boxes on A frame and big boxes on rear bumpers need their heads read.

What you are saying is by putting a heavier tongue in it reduces the allowable downward weight on the towbar.

Have never considered or even seen that mentioned and I am sure that 99.9% of anyone else hasn't either.

I see your point but I wonder if anyone has noted this anomaly in the towing regs.

And if in fact it makes any difference as when I asked the NSW RTA they said they had no rules on towball weights at all.

The only restriction seems to be the capacity of the vehicle as stated by the manufacturer.

An interesting theory.

Surely they have regs that say you cannot exceed the vehicle manufacturers limit or the towbar manufacturers limit whichever is lower.

From the reply i got from the NSW RTA regarding another question The last sentence is what I mean


Yes,you can tow the caravan under the following conditions.

1 / You do not exceed the vehicle manufacturers tow capacity of 2500 kg for the vehicle, ( this means that the caravan cannot exceed its GTM, of 2500 kg,even though it has an greater ATM ).

2 / Your vehicle must have a compliant tow bar fitted and it must be correctly rated,the RTA do not have any requirements on "ball weight".

Regards

If the weight of the WDH does actually count toward the ball weight limit, that would suggest that the ball weight limit is a factor of the tow bar itself, which seems logical, but the tow bar manufacturers say that installing a bigger and better tow bar (if one is available) won't increase the allowable ball weight limit which is set by the motor vehicle manufacturer and can't be exceeded.

That's why I had the second question about what the ball weight limit is based on. If it's the axle load limit, then I'd say using a WDH would benefit in the way it distributes the load more evenly across the axles.
But I suspect that the ball weight limit might be determined by something like the center of gravity of the vehicle payload (amount other things).
That would explain why my car has a lower than expected ball weight limit because it's a Jeep Wrangler Unlimited (4 door with the long wheel base) and it has a relatively high center of gravity as described by the warning sticker on the sun visor.
The horizontal load limit on the other hand seems to be a factor of the weight of the vehicle and the wheelbase, since the 2 door (short wheel base) version of the wrangler has a much lower horizontal towing load limit, but the ball weight limit is only 10kg's less.

Very interesting, but as Graham says, there is very little official information around about ball load limits apart from "don't exceed it"...

I'm towing a 16' 2005 Jayco expanda pop-top. (plus wife and 3 kids and their accessories...)

The towing weight limit is phrased as follows.

You can tow the vehicle rated weight or the rated weight of the towbar WHICHEVER IS THE LESSER

Buy a real tow vehicle like a Cruiser that has a rated weight of 3500kg and a towball weight of up to 350 kg or a Patrol with up to 3200kg LOL.


The amount of weight shifted by the WDH is not a lot.

Your axle ratings are set by the manufacturer.

Most people who tow vans and check their weights do so with a WDH fitted

and I have never ever heard of anyone, including me, worrying about the

weight of the actual hitch.
Im fussy about legaliies and have never considered that, Perhaps I should, but in my case it doesnt matter as I have about 30kg spare..

With regard to 'missing the point' - Might I stress that the weight distribution hitch mentioned in my response above, is part of the vehicle - It is not just a tongue attached to the rear chassis - it actuall fits across the rear of the vehicle and extends toward the front of the vehicle on each side.

This is distinctly different from a ' Hayman Reese' style WDH which fits onto the A frame of the van.

Sorry I didn't make this clear in the thread.

I mention it now because it must be really confusing to have two differing types of WDH and I suspect this is not commonly known - I certainly didn't until I read about them on one of the RAC towing guides online (wish I could find it now with the diagram). As stated - this WDH is part of the vehicle - no weight whatever included on the tow ball.

Cheers - Phil

A Hayman Reece WDH Hitch fits into a 50mmsq box section in the towbar.


The only part that is attached to the A frame is the two pieces that you pull the tensioning legs up to and weigh hardly anything.

The towbar extends forward under the chassis with up to four bolts on each leg.

I have never seen anything that would put significant weight on the ball and have never heard of what you are talking about.

A manufacturers name and a link would be good

See These pics and link to show the Hitch fits in tow bar

Image Could Not Be Found

Image Could Not Be Found

[url=http://www.haymanreese.com.au/products.htm]HR Products[/url

Thanks for the pics Graham - they are said 'to speak a thousand words' and they help in this case.

The top pic has some gear that hangs off the A frame, however slight, and from the coupling back is included on part of the ball weight.

The lower pic is they type I was trying to describe - same principle similar build - and is part of the vehicle itself - excluded from the ball weight - which is what we were trying to establish for Glennco .... my slant on it anyway.

Cheers - Phil

I guess I should add, that because of the design of the lower pic WDH - this increases the capacity of the tow ball - in my vehcile - from 135kg to 250 kg - so there is no need for the chains and lever style operation in the top method WDH. - Phil

You entirely miss the point of how they work.

When you measure the ball weigh of a van you disconnect it from the car and drop the bars of the WDH and weigh the A frame of the van by putting the ball socket on a scale.

The bars to do their work actually pull the A frame UP and thereby straighten the joint between the car and the van. As said in my answer above it does NOT decrease or increase the ball weight

By this action you transfer some (a little) weight forward to the front car wheels and some (even less) back to the van wheels. This equals up the rig and restores some steering weight to the front wheels

Putting one of those Towbars on will only increase your towing capacity IF YOUR CAR ALLOWS IT otherwise it is the lesser figure of the two That is of the car or the towbar.

If you have a 250 kg ball weight you SHOULD use a hitch as in the top pic Once you have you would never tow without one

In my opinion anyone who doesnt use one with that weight should be shot.

What the OP meant I think was did the part that sticks out from the towbar become part of the ball weight because it is not actually part of the bar.
IMHO no However I will ask my contact at HR and post the result when I get an answer.

Graham - Sorry you seem upset at the legalities of the weight allowance on my rig - but suggest you don't shoot the messenger - take it up with the RAC and Manufacturers.

RAC only confirm what my Owners Manual state.
Phil

Im not upset at all

Just pointing out that because the towbar says it is rated to a certain figure it doesnt mean that by fitting it, the vehicle can tow that amount UNLESS it also is rated to the towbar limit.

If your vehicle is rated to that very good.

EG Pre 1995?? 80 series were rated to tow 2500kg if I remember correctly.

A 3500 kg towbar would fit on the vehicle but it still couldnt tow more than its rated 2500kg. As that is the lesser of the two figures.

Thats what I was meaning. I wasnt meaning you couldnt do it and the lower picture was of a towbar .

The top one is a Weight Distributing Hitch which doesnt figure in the ball weight.. im out of here.

Graham,

I understand perfectly what you are trying to say. the photo at the top is a proper WDH I would call the bottom one a heavy duty towbar which distributes the weight on the chassis of the car. Can't see how it would alter the allowed tow ball weight, in fact it may lower the towball weight as it is an addition weight placed behind the rear axle

Have to agree with you Rob on the issue of legal limits of the vehicle being fixed.

Research shows the allowable weight on the ball will differ, depending on the type of 'hitch' you have on the vehicle.

I have a copy of a document from 'Caravan Industry / RACQ Towing Mass Limits' (Copywright) whiich from memory covered all vehicles in Aust - the one page I copied covers 20 Mitsubishi models.

The 'Ball Max Max' is 250 kg - but there is a reference to 'Conditions' which states 'Load Level hitch req. above 135kg'

So I have been remiss in babbling on about WDH allowances (sorry about that).

The technical term which allows my vehicle to handle the max ball weight is the 'Load Level Hitch' which is fitted and stamped to carry 250kg.

From memory I only found about 4 or 5 vehicles in the whole range of vehicles listed, which could handle something like 150kg ball weight or greater, without 'conditions'.

I have just tried to relocate the document in full from the RACQ website, but my search criteria doesn't turn it up. Great guide for all if anyone can locate it.

Another top document I dragged from an earlier computer is 'Towing Guide - A practical guide to safe towing' put out by Mitsubishi and Big 4 Caravan parks'. I have it as an Adobe document but wouln't have a clue how to arrange a link. Can't find it on the web again and when I try to 'Copy & paste' I can get the text, but not the pics.

Frustrating being a 'pre -boomer' I can tell ya.

Cheers - Phil

Any Cruiser or Patrol can handle more than 150kg without any assistance.

A hitch is normally a Hayman Reece Weight distributing Hitch.

A towbar as in the lower picture I posted is just that A towbar.
It does not distribute weight "along" the chassis. It just hangs from it and pulls tha rear down when loaded

They come in various makes and weigh capabilities.
Eg straight tongue ones like on a Commodore are I think Class 2 and can handle towing up to about 2000kg Above that you need the model pictured.

The "Hitch" is the part that is attached to the towbar and comes in several types and capabilities. This is what distributes weight along the chassis.

There are the Camec 2 and 4 bar equalisers for light vans.

Then there are several weights of Hayman Reece weight Distributing hitches.

These have the same head that slides into the receiver on the "Towbar" Or Receiver if you like

they have different thickness arms to give more weight capacity.

They are part of the car and have nothing to do with ballweight of the van.

This is weighed completely unattached from the tow vehicle and any other bits.

If your vehicle manufacturer recommends a WDH it is to assist the car to handle the weight with regard to the weight distribution through to the front wheels.
The fact that it allows a heavier ball weight than recommended is not to increase the cars capacity but to allow for any vehicle deficiencies above a certain limit.

The cars ballweight amount is set by the manufacturer and as I said putting a heavier towbar that may exceed your cars legal limit does not allow you to load it up past that.

Perhaps a read of this will help you understand the terminology and methods


Safe Towing



http://www.towingguide.com.au/couplings.html


Hayman Reece

Cheers

And here


towbars etc

And here is a good explanation


WDH

Hopefully thats what we said.

"there are some differences of opinion in the towing industry"

"Hopefully thats what we said. "

Yep. Differences of opinion. That's what we said. :-)