#158555  by rogertee
 Tue Feb 04, 2020 8:47 am
I have a year 2000 Elddis Typhoon XL caravan. the hitch has been changed from the 50mm English anti-sway system to a 17/8" AL-KO one with a standard height ball. My vehicle, a Ssang Yong Rexton the ball height is 450mm and when our horse float is attached it is almost perfectly level and tows like a dream. However when my 'van is attached it is very obviously down at the back and at around 85kph, especially downhill it starts to sway. If I measure the hitch height on the 'van when it is level it is 380mm. Is this the cause and if so should I have a new towing tongue made of correct height, to accommodate the 50mm long neck ball and refit the English hitch? Any advise will be gratefully received, thank you.
 #158559  by mattn
 Tue Feb 04, 2020 9:18 am
The EC Directive 94/20/EC (The standard that all towbars are designed to) states that the tow ball height should be between 350 and 420mm from the ground with the vehicle in a 'laden' state.

What is the towball weight of the van. Its is more likely to cause sway having it too light than hitch height. My tow ball is about 450mm (laden) and my van (around 1400kg full)) tows nicely with just 70kg on the ball (Although I prefer to run 90kg -100kg. )

Alko have a max ball weight of 100kg.
 #158582  by rogertee
 Tue Feb 04, 2020 6:46 pm
thanks for that, is there an easy method of checking the tow ball weight? i did have a few thoughts on the trip we have just done. leaving home we had 2 full 9kg bottles in the locker, 40 litres of water and the awning along with a large heavy gazebo all forward of the axle and it seemed to be more stable. coming home there was no water. Could this have made a difference?
 #158584  by mattn
 Tue Feb 04, 2020 8:06 pm
Easy way to measure tow ball weight is to use bathroom scales which easily handle 100kg. I bought a set of $10 Warehouse specials after getting caught by my better half sneaking the good bathroom scales back into the house :lol: . Ideally use a block of wood to measure under the actual ball, but if you sit the jockey wheel on the scales you get it close enough if you subtract about 10%-15% (i.e. 100kg under the jockey wheel will be about 85kg- 90kg on the tow-ball.)
 #158585  by Andrew and Debbie
 Tue Feb 04, 2020 8:19 pm
One of these makes it easy to weigh https://www.supercheapauto.co.nz/p/troj ... 78838.html

 #158598  by Nut17
 Wed Feb 05, 2020 5:29 am
You also need to be aware that the van must be as level as absolutely possible to accurately measure the ball weight. If the nose is even slightly elevated, more weight is carried by the rear axle, effectively increasing the measured ball weight. Obviously the reverse is the case and an inaccurately lower ball weight will be measured if the measurement is taken with a nose down attitude. Obviously, this is only an issue with tandem axle vans with independent suspension. Single axle and tandem vans fitted with load sharing leaf springs will have a minimal discrepancy with a nose up / down attitude.
 #158887  by rogertee
 Sun Feb 16, 2020 10:21 am
Thank you all for your advice, it has proved very helpful. by placing two full 20lt water containers (my potable supply)as far forward as possible I have achieved a drawbar weight of 86kg (give or take 200gms) and the van now tows beautifully.
We live and learn, even at my age!
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