Towing 2300kg van with Challenger 2.5 TD Auto (and generally)

Interesting!!

What is the ball weight of your van.

The down load ball weight is maximum of 180 Kg, we had to have our van modified to have an empty down load ball weight of 110 Kg.
We have an empty van weight of 2450 Kg with a pay load of 600 Kg.
With careful loading we have not been over 165 Kg however, we only have around 450 Kg payload which includes 160 Kg of water.
The remainder is Generator, Fuel, Clothing, Food & the other essential's which allow for 5 to 8 days free camping.

"we had to have our van modified to have an empty down load ball weight of 110 Kg"

Can you tell me what modifications were made to the van to achieve the reduced ball weight?

We had the door mover to the rear of the van in front of the unsuit & the wheels moved forward.
In having this done the interior design had to be altered to suit the door relocation.
Basically, the LH side internally items had to be moved forward the same distance of the door width.
We also had a larger fridge installed which is located at the rear axle position & the water tanks were set further to the rear. (1 tank between the axles & the other behind the rear axle.)
The only fault I found was that I have to have the water tanks filled to a minimum of 3/4 full other wise the van tends to fishtail, especially down hill at around the 85Kl/Hr. With tanks 3/4 full, I have had the van to 100 Kl/Hr + & it trailed perfect.

So you have a van with an ATM 50kg more than the tugs capacity with a loaded Ballweight of about 6%.

No wonder it fishtails down hill.

You say you have 450 kg payload so where does the rest go that you list

Thanks TomH for the details. Sounds expensive!

I note that the recommendations I have seen for ballweight seem to suggest 8-15% or 7.5-12.5% when loaded and ready to go for the holiday.

Unloaded, my Tow Ball Weight TBW with van unhitched and on a scale under the pin (the jockey wheel is back a foot or more and would give an incorrect TBW) at Tare is 250kg being 14.4% of 1740kg. (Tare is no gas and water in tanks and no added load)

Loaded after hitching and with the weight distribution hitch WDH connected and tensioned I expect it to be between 258 and 276, depending on loading in box on A Frame and in tunnel boot at front of van and under bed. I should make clear that the tow ball weight is a defined term measured with the van disconnected and doesn't change, it's just that the WDH redistributes the weight previously on the jockey wheel.

When first connected the towball puts say 145% of the TBW amount on the back axle and reduces the weight on the front axle by 45% of the amount of the TBW, leaving the van axle with unchanged weight.

The tensioning of the WDH adds about 34kg to my van axle weight (and reduces the weight on the back axle of the tug by 98 and increases the weight on the front axle of the tug by 64) (all compared to what it was after the van was first hitched and with jockey wheel removed from the van).

With the expected 35kg heavier loading in these front areas, my ball weight as a percentage of total loaded van weight will likely fall between 279 kg being 12.5% of 2237kg incl 254 litres of water and 276kg being 13.8% of 2003kg incl 20 litres of water.

The weights in the range in the paragraph above keep me well below the 3000 towing capacity, and below:
a) the 1990 van axle weight,
b) the Gross comined mass of tug and van,
c) the ATM of the van,
d) the tug maximum back axle weight,
e) the tug maximum front axle weight,
f) the tug maximum payload
(even after the transfer of the towball weight from the the jockey wheel to the towball when the van is hitched and after the redistribution when the WDH is connected and tensioned).

Those weights keep me within the recommended ranges of towball weight to loaded van weight both before and after hitching of van and after connecting the WDH.

The TBW measured as defined does not change but the weight of the van effectively does by the 34kg weight redistributed back to the van from the tug by the WDH to re-level the tug.

Was replying to MaxC3 sorry Yes I know all that

Hi Tom H,
I don't have any other items to make the designed 600 Kl pay load, therefore I am towing with less than maximum.
Fishtailing will occur with any duel axle set up which does not have independent suspension to each wheel. in short, when the unit starts to sway the weight of the van is transferred to one side & this side the axle centres are closer to each other, when the weight moves to the opposite side the axle centres change therefore the van tends to steer itself from side to side.
I don't know the correct terminology or the calculations (if any) but that's how fishtailing occurs.

Axles dueling Thats different .

Strange that my 25 footer never did that.

However everyone to there own.

No matter how you try to fudge numbers they basically stay the same and if you have to go to all that trouble to appear to stay legal you have the wrong tug or the wrong van.