jegog wrote:

---

I am considering upgrading to a caravan and have been doing my research.

I think I have my head around the various weights. I just reworded the terms to common English and used the caravan and vehicle weights as the references for the other terms.

But eventually I came to WDHs.

Reading what people wrote just confused me as I saw it as being a turning moment and centre of gravity problem but it's been over 60 years since I did that sort of calculation and the complication of springs in the suspension, type of spring(linear or progressive) bewildered me.

Then I stumbled across this video https://www.youtube.com/watch?v=kCgRiVNaXFc

The intro is a bit over the top but the description on how WDHs work is excellent.

Basically the WDH is a torsion bar which imparts a rotation onto the vehicle and the caravan.

After explaining the theory he then cautions about driving into a culvert or drain where the front wheels of the vehicle and the wheels of the caravan are higher than the rear wheels of the vehicle. 

Best watch the video for that.

If I do fit one I will only use it when on the bitumen and leave it off when on gravel.

---

 Hi Dennis.Could I take this opportunity to thank you for posting this video.Not knowing much about "attachments" etc, many times over the last few years I have asked members to view this video,in the hope that doing so could correct the misunderstandings that many seem to have about what is viewed as the "cure it all" for towing problems.WDHs are used only by those with little understanding of weights and physics,as they create all sorts of problems that many members seem not to understand.Increased towball overhang initially causes increased weight on the rear axle of the car,and the use of the WDH can increase the dangers of oversteer.This is just the beginning,but generally a WDH is used only by those who do not understand physics,and are trying to make a car do things for which it never was designed.Get a bigger car or a smaller van.My car and van run at GCM of 6800kg,legal on every axle,and no WDH.Do it once,do it well.Cheers

 

Rob Driver wrote:

---

jegog wrote:

---

I am considering upgrading to a caravan and have been doing my research.

I think I have my head around the various weights. I just reworded the terms to common English and used the caravan and vehicle weights as the references for the other terms.

But eventually I came to WDHs.

Reading what people wrote just confused me as I saw it as being a turning moment and centre of gravity problem but it's been over 60 years since I did that sort of calculation and the complication of springs in the suspension, type of spring(linear or progressive) bewildered me.

Then I stumbled across this video https://www.youtube.com/watch?v=kCgRiVNaXFc

The intro is a bit over the top but the description on how WDHs work is excellent.

Basically the WDH is a torsion bar which imparts a rotation onto the vehicle and the caravan.

After explaining the theory he then cautions about driving into a culvert or drain where the front wheels of the vehicle and the wheels of the caravan are higher than the rear wheels of the vehicle. 

Best watch the video for that.

If I do fit one I will only use it when on the bitumen and leave it off when on gravel.

---

The decision to fit or not to fit a WDH should not be based on a UTube video or an opinion from some on a forum.

The vehicle manufacturers recommendation should be paramount in that decision. Their recommendation is based on your safety.

It is a good idea to disconnect the WDH in off road situations or where manoeuvring into tight spots may cause strain on the mechanical aspects of the unit.  

---

 The recommended use of a WDH "based on your safety" is simply a Red Herring used to camouflage the inadequacies of the vehicles concerned,with their lightweight rear axles. The ONLY way these cars can safely get anywhere near their claimed PIG TRAILER tow capacity,whilst running the generally accepted towball weight of 10% of ATM, is to get weight off the car's lightweight rear axle.There is no mention,of course,of the inherent dangers of increased towball overhang,which include extra weight on the car's rear axle,which the WDH first creates,then moves! There is no reference to increased yaw, with the associated tendency to have the "tail wag the Dog". There is no reference to the fact that a WDH does not alter towball weight,but increases weight on the van's axle group.If the van is loaded for travel,this can result in the ATM being exceeded,so the van is overloaded,unsafe and uninsured.There is no reference to the fact that a WDH creates what is,in effect,a "stiff arm" from the car's front axle,through the hitchpoint, to the van's axle group. There is no reference to the enormous stresses imposed on the car's chassis,the towbar structure,and the van's chassis if the vehicle is used on anything but a nice flat freeway.Can you even imagine  all the stresses on your gear when you drive  through washouts etc,or even into servos? There is no reference to the fact that a WDH is likely to assist in having the car overturn too in the event that the van goes R Sup.  I could go on,but there never is reference to,or even acknowledgement of,these negatives by proponents of WDHs who rabbit on about keeping their vehicles level,and riding smoothly,or any of the many other claimed advantages.New members would do well to use the "search" button on the forum rather than heed advice to ignore the simple truths that are included  in the video being discussed.Reading books by Collyn Rivers,a man with over 60 years experience in physics and dynamics etc,suspension design for major car companies,army experience and extensive outback travel will only confirm information contained in John Cadogan's video on the subject. Simple physics,simple facts,simply indesputable. Getting a more suitable car,or a more suitable van negates any need for the over rated "cure it all" WDH.Cheers

-- Edited by yobarr on Sunday 20th of February 2022 02:40:23 PM

Good morning Mr Yobarr,

I have stated on at least a few occasions that I no longer wish to participate in any debates with you regarding weight measures and towing requirements.

The vehicle manufacturers recommendations are what owners and potential operators that are intending to tow, should be heeding.
They designed the vehicle.

I will say no more.

Rob Driver wrote:

---

Good morning Mr Yobarr,

I have stated on at least a few occasions that I no longer wish to participate in any debates with you regarding weight measures and towing requirements.

The vehicle manufacturers recommendations are what owners and potential operators that are intending to tow, should be heeding.
They designed the vehicle.

I will say no more.

---

 Hi Rob.You say that you "no longer wish to participate in any debates with you regarding weight measures and towing requirements". This being your intended course of action,I wonder why your post followed my post,where I thanked Dennis for posting this video.Your post effectively said that the advice in the video,along with advice of "some on a forum" (me?) should be disregarded when the use of a WDH was being considered. And your suggestion that buyers should heed manufacturers recommendations will only give hope to those who know little of weights.The reasons for this are included in my post today,at 11.11am.And all this time I had thought that you'd finally realised that I know what I'm talking about,with my thoughts being confirmed by advice and information contained in books and videos by both John Cadogan and Collyn Rivers. Perhaps not? "Head in the sand" comes to mind.As I have stated many times before,the single biggest positive contribution to caravan and car safety would be to extend the law that currently  applies to vehicles with a GVM over 4500kg,to ALL towing vehicles.To refresh your memory,it is ILLEGAL for any vehicle over 4500kg GVM to tow a PIG trailer that weighs more than the towing vehicle.To clarify,the weight on the wheels of the towing vehicle must ALWAYS exceed the weight on the wheels of the caravan.This is simple physics,and common sense,and is designed to minimise the chances of the "Tail wagging the dog".Cheers

jegog wrote:

---

My advice would be that if you are contemplating fitting a WDH to ask your friendly car dealer.
If the dealer recommends fitting the device then ask whether the vehicle warranty would cover any damage to the vehicle attributed to the device.
Should the dealer answer in the affirmative, get it in writing.
Otherwise you are installing an anauthorised modification entirely at your own risk.

---

 Good luck with that too,Dennis.Last year I attended the premises of  a new-car dealer where I met a man who had just agreed to buy a new Ram 1500, trading his LC200,because the Ram "can tow 4500kg" and "eats utes for breakfast". Seems he had a 3500kg van,and had realised that,despite the hype of his LC200 having a GVM upgrade,it wasn't really up to the task.He planned to sell both the car and van,and had intended to get a Ram 1500 and a new 4000kg ATM van.After I pointed out to him that the Ram was even less capable than was his LC200,and why, he thanked me profusely, cancelled the order and left,vowing to do more homework.Car salesmens' incomes are often commission based,so the LAST thing they're going to tell you is anything that could jeopardise a sale.Several people have contacted me,via PM,for advice when buying new cars,and I have saved some from making BIG mistakes.WDH are used to camouflage a problem that would not exist if the correct car was chosen in the first place.Cheers

Gundog wrote:

---

When yobarr responds to anything regarding Weight Distribution Hitches, it is purely to get a reaction to those who support the use of WDH's when vehicle manfactures either require or reccomend their use within their owners manuals or Towing Guide.

But rather than post a reasonable response he drags out the old chestnut vehicles over 4500kg cannot tow pig trailers, which has absolutly nothing to do with the comon vehicles used today towing caravans, And I understand that when Yobarr posts a non paragraphed respose which is very hard to read is because he using a tablet I presume, but that issue could be avoided if he selected within his settings to go to the full site.

One of the gentlemen he referenced, in the past I have had a lenghy back and forth discission about WDH's, he withdrew from the discussion when some of his information was challenged.

When Not to Use Weight Distribution

Some vehicles, especially those with unitized bodies and frames, explicitly state that a weight-distribution hitch is not to be used. This is because the forces on the hitch receiver and tow vehicle frame from a weight-distribution hitch are very different from what a normal ball mount would do. In some vehicles, this could cause damage to the structure of the vehicle.

Oftentimes, rental trailers are equipped with surge brakes, along with many boat trailers. Most chain-style weight-distribution hitches arent compatible with surge brakes, so be sure to use a weight-distribution hitch that clearly states it will work with surge brakes when towing a trailer so equipped.

Some trailers have a pole tongue instead of an A-frame tongue. A pole tongue uses a single frame member that extends from the front of a trailer instead of two pieces forming an A shape. Weight-distribution hitches use brackets that attach to the trailer A-frame to support the arms at a certain angle. When towing a trailer with a pole tongue, many weight-distribution hitches will require the use of a pole tongue adapter.

---

At the risk of confusing you,could I ask whether you think that there could be a GOOD reason for having a law that says if the towing vehicle has a GVM in excess of 4500kg any PIG trailer that it tows MUST,at ALL times,have less weight on its wheels than does the towing vehicle? No? It's called simple physics,and is easy to understand if looked at objectively.To help you out,could I ask if you've ever heard of the "tail wagging the Dog" which is what occurs in an emergency situation where the trailer (van) weighs more than the towing vehicle.It all will end in tears. Do you not think that the same simple laws of physics might apply to ALL towing vehicles,or is that a bit hard for you to comprehend? And you claim  to have had "a lengthy back and forth discussion about WDHs,he withdrew from the discussion when some of his information was challenged" Who challenged this information when only the two of you were in that discussion? You can waffle on,thinking you know about WDHs,and you are entitled to your opinion, no matter how misguided you may be.Unfortunately,with weights and the effects of using a WDH,there is no room for opinion. Your weights are either right,or they are wrong.And it seems that you've been reading posts from another member who claims that my posts are non-paragraphed? You're both wrong,unless the punctuation that shows on my screen is different from what you're seeing? And,for the  record,I scored an A+ pass in English when applying to matriculate to a major university,some years ago.Have great day.Cheers.

Are We Lost wrote:

---

yobarr wrote:

---

........

And it seems that you've been reading posts from another member who claims that my posts are non-paragraphed? You're both wrong,unless the punctuation that shows on my screen is different from what you're seeing? .......

---

This is what I see (I pasted an image) .... not very easy to read. Perhaps you should look at double spacing between paragraphs. You can probably configure your device to put a space after commas and full stops as well. All help readability.

As you would know from previous posts I am a strong proponent of WDHs in most cases when towing heavy vans. Suspension modifications that do nothing to redestribute weight back to the front wheels mean less tyre grip at the front, and more tyre grip at the back ... an unhealthy handling situation.

For the subject of this thread, I would not use a WDH offroad, although I do on good unsealed surfaces. If speed is low, then the need for a WDH reduces. Service station entrances are never a problem, but if there was a deep culvert, then maybe the WDH should be disconnected. Sometimes there is room to traverse the culvert at an angle, thus reducing excessive tension.

 

-- Edited by Are We Lost on Sunday 20th of February 2022 07:35:33 PM

---

 Yobars text is no different to everyone else's on my device (mobile phone) ,perhaps you need to check the settings in your device.

Interesting. I am using Frirefox on a Windows PC and posts from others look OK.

A quick check in HTML format, I see no paragraph marks but do in Gundog's post. The same when I paste into Word. Rather than digress this thread further I will raise it as a separate subject in the next couple of days.

oldbloke wrote:

---

Are We Lost wrote:

---

Interesting. I am using Frirefox on a Windows PC and posts from others look OK.

A quick check in HTML format, I see no paragraph marks but do in Gundog's post. The same when I paste into Word. Rather than digress this thread further I will raise it as a separate subject in the next couple of days.

---

 Thats because it's intentional. So don't bother. Yobarr will continue to post with no spaces or paragraphs. It must be intentional. Which I find interesting because he claims to be an "A" English student. I can only assume it is to annoy, or agitate members. There is no other explanation. 

---

Hi oldbloke

 That style is most definitely intentional.

It is a style that has come about on forums and some social pages with the increased use of mobile devices as opposed to old desktop computers.

The main reason that this style of typing is taken up is to prevent or at least make it extremely difficult for many contributors to highlight or divide comments so that they may receive separate comments or at least become the subject of discussion.

The ability to use a finger to separate text is very difficult so as a result the delinquent user of this style gets away on the most part with not being questioned on the hidden detail within his jumbled ramblings.

This style also encourages comments of * read my comments or you didnt read my comments* etc. 

We have all seen that said on here by those who offend with that style of typing.

Fortunately most members on here respect others and type to an acceptable standard. 

I saw on a technical information and discussion forum only last year where a member repeatedly used that style when posting and after a few warnings that member was removed from that list.

As have others, I have suggested to our Yobarr to use the space bar paragraphs and punctuation on several occasions to no avail.
I liken it to wearing a hat at the dining table, where it doesnt stop you eating it is just unacceptable, rude and displays no respect for others at the table.

It wont change until a change is implemented.

Apology to the op for the off topic post.

Gundog wrote:

---

When do I disengage my WDH. Only when Im reversing on to a site.

 

When and how do you decide to use a WDH.

The first thing to do is consult you vehicles owners manual and your manufactures Towing Guide. ( In the case of my vehicle I am required to use a WDH when towing over 1800kg)

You get your fully loaded Vehicle and Caravan as if you were leaving on you caravaning adventure, on reasonable level ground with caravan on it's wheels and jockey wheel, raise or lower the jockey wheel to get the caravan level. This can be in 2 ways either using a long spirit level or a tape measure, measuring the height at front and rear of the van.

With the van level now we measure the tow coupling height. example 410mm.

With your towing vehicle level, measure the height of the towball, if it's not close to 410mm plus 7mm for every 100kg of ball weight, then you will to adjust the height of the hitch to get it close to the 431mm. If you cannot adjust the height of your hitch, you may have want to borrow an adjustable hitch before buying one.

Your tow ball is at 431mm, now connect you vehicle to the caravan, with the jockey fully raised bounce up and down on you A frame to settle the suspension. Stand back and look at the attitude of your vehicle and caravan, if it looks to be fairly level then take it for a short test drive to check the steering and braking. if everything is good you dont need a WDH.

If its unlevel with the front of the vehicle high, its more than likely you might need a WDH. See if you can borrow one test fit it according installation instructions.

---

 There is little doubt,Graham,that you believe that this is good,but it's 19th Century (sic) stuff. There are way too many variables for your method to be of much use. Variables which have a big effect on your calculations include wheelbase of car,towball overhang,and spring rates,but there are others. No doubt your intentions are good, but this method has so many flaws it almost is useless.Cheers

 

-- Edited by yobarr on Tuesday 22nd of February 2022 01:23:54 PM

In fact WDH systems have been around a long long time. My father bought a new tandem axle Franklin van back in 1969 and there was a simple WDH system available then, two spring bars and a hitch receiver for the tow bar end with chains and receivers on the draw bar. They were a fairly simple arrangement.

I have been using a WDH on my van when traveling longer distances, i don't worry about using them all the time as the van and tug sit pretty level when hooked up anyway.
To be honest to me they don't make an awful lot of difference to the feel and handling, but they would be assisting in small ways.

That said when I lift the bars via the holders on the draw bar the rear of the vehicle does lift slightly. As always it does come back to having an awareness of weights in the van and vehicle, staying within what the manufacturers deem safe.

I do have airbags in the rear of the vehicle too which would assist in maintaining the level attitude when the van goes on...but I believe if you can assist even a little in pushing some of the weight back to the front of the tow vehicle it makes sense. Any tow bar is creating a cantilever effect when weighted behind the rear wheels.

Obviously if you need to put a huge effort in to just pull the WDH bars up on to the receivers on the draw bar, and then use a 5' pipe to bring them home there is a problem. It would be quite easy to over load the WDH spring bars by being greedy with the chain links leaving the whole thing way too tight.

Basic physics will tell you that any excessive twist between tow vehicle and trailer the WDH system will be experiencing abnormal stress and could cause damage or be damaged.

I take them off as soon as I go off the road or when reversing on to a park.

Very true that a WDH is primarily for highways and definitely not offroad.

Airbags may be better than nothing but typically not for leaf springs due to risk of chassis damage. Levelling is not very important for road safety. What matters is reducing the additional weight on the back wheels and restoring lost weight to the front wheels. If there is a significant imbalance in weight between front and back, there will be a siginficant difference in tyre grip on the road from front to back.

-- Edited by Are We Lost on Tuesday 22nd of February 2022 10:45:35 PM

With leaf springs I thought that airbag were added and the leaf springs remained and so in reality the load would be spread over three chassis points instead of two. Adding air bags is just increasing the suspension load capacity.