Supposition. I have a tow capable of 2.5 ton. Fully loaded my caravan is 2.4ton (like to think it wouldn't be that heavy).
So, if I'm now towing full height van, say 2.9m high with aircon, rather than a poptop with a lower chassis, I personally would want to consider at least anti sway, likely WDH. (I Have rear suspension airbags, but let's not confuse me now on that topic and WDH.....)
2 dealers have said neither would affect my ATM. However, my logic says, the weight of both has to be countered for somewhere. Does it goe on my van or tug? The dealers say it , The weight, goes on tug.
Im asking from a legal perspective. My logic is if I weigh van and tug, unhitched them n weigh tug, the ATM will be up due to WDH and anti sway that I left on the van. Here's where the dealers say no, it goes onto tug.
Does anyone know? I'm pulling my hair out here and going white, not grey, prematurely, trying to work it all out Before I purchase a new van...
MJ, this topic has many discussion threads.
1) The role of a WDH is to relieve some of the forces on the tow ball and transfer this to the tow bar.
2) The other purpose is to level the van/car assembly. I have air bags and in order to have the car and van perfectly level, I use a combination of chain links and pressure in the bags.
The van is a 2.5t full size variety, 21'6. The ball rating is 250 kgs, but had it checked and it came in at 275 kgs once on the road. The tug is a 200 series Landcruiser which has a ball weight of 350 kgs.
I have my WDH on the sixth link counting from the bottom and the bags at 8 psi. When all measurements are taken, the whole show is level.
WDH are NOT a swaying device. You can get a shock absorber type setup that will slow down sway on the hitch. Some vans, mainly Europeans, have a friction pad in the hitch that is meant to cause friction on the ball and reduce swaying.
You will find that if you have your van and tug perfectly level, there will be next to no swaying. The only time we encounter some swaying is in high wind conditions, in which case, slowing down to 80 kph fixes it.
Hope this helps and does not confuse you.
Larry
PS: a number of forumites will also have their own version of this.
lets say the weightof the anti sway and load leveller is 50kg, if you are running that closes to limits and was concerned I would look at other options with tug and van.
Myself
My van and tug are loaded with what I need, not 100% on weight but it feels good and stable, tows well and not sure off weights but I am happy with set up.
cheers
blaze
The dealer was correct. Neither will or ever could affect the ATM or GTM as they are static maximum manufacturers specified mass's that cannot be weighed. Ozjohn.
-- Edited by ozjohn on Sunday 11th of May 2014 03:53:18 PM
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Retired Engineer, Ex Park Owner & Caravan Consultant. Holden 2.8 Colorado - Roma Elegance 17'6" Pop Top. Location: Mornington Peninsula Vic.
The dealer was correct. Neither will or ever could affect the ATM or GTM as they are static maximum manufacturers specified mass's that cannot be weighed. Ozjohn.
-- Edited by ozjohn on Sunday 11th of May 2014 03:53:18 PM
Ok, I'll have a go at answering this question (some of this has been mentioned)..
The simple answer to your title question is 'No'.
I gather you're asking if you should use a WDH with a new van you're considering buying, that may weigh up to 2.4 tonne.. The answer to that question is 'Yes'.
As for terminology..
ATM (and GTM) and GVM don't change - they are all figures set by manufacturers.
ATM and GTM are set by the caravan manufacturer. GVM is set by the vehicle manufacturer. (In your quest for answers also consider GCM (Gross Combined Mass), which is also set by the vehicle manufacturer)
Also consider..
'Anti-Sway Control' and 'Weight Distribution Hitches' are different things that do different jobs. Air bags on a vehicle's rear suspension do not do the same thing as a WDH - But you probably know that already..
It seems you're asking what happens to the weight when you fit a WDH?
When you hook up a caravan, 100% of the towball weight is loaded on to the rear axle.. When you fit a weight distribution hitch, it transfers percentages of the towball weight to the vehicle's front axle and the caravan's axle(s)..
The actual weights and percentages transferred vary from rig to rig, and it varies on how the WDH is set up, but when it's set up correctly the weight transfer is in the order of.. Weight transferred to.. Vehicle front axle - 40 to 45% Caravan axle - 10 to 20% Vehicle rear axle - 40 to 45% remains on the rear axle.
Thanks all. My main concern was whether, if pulled over and weighED, car seperate to van, would the hitches affect my ATM? I'll take ozjohns answer on that, cos it suits
And Jim, I've noted ur percentages for future reference.
Thanks again to you all.
Thanks all. My main concern was whether, if pulled over and weighED, car seperate to van, would the hitches affect my ATM? I'll take ozjohns answer on that, cos it suits And Jim, I've noted ur percentages for future reference. Thanks again to you all.
Just to reiterate what I think you already know, the actual laden weights should not legally exceed the ATM and/or GTM etc. Ozjohn.
PS> Bet you never get pulled over an weighed unless the rig appears to be in a grossly unroad worthy condition.
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Retired Engineer, Ex Park Owner & Caravan Consultant. Holden 2.8 Colorado - Roma Elegance 17'6" Pop Top. Location: Mornington Peninsula Vic.
