Thread: In Sydney need advice instability when towing

Originally Posted by discotwinturbo

Your economy is great.
I regularly tow a 3.5 tonne triple axle horse float, and freeway sees it had 17.5 on the trip computer, whine taking into my constant 1.9-2.0 lp 100 difference puts it at 19.5....my Touareg does the same job at 16.

Brett.....

Best to measure it - with the tyres you've got on, your trip computer could actually be pessimistic!

And of course, your D4 is carrying one or two accessories ........

Cheers,

Gordon

I have all the fuel dockets for this trip but have not done the sums ? !
Will post when I get home will be a total of over 7000 Kim's. 90% with a 3 tonne van on the back. Computer went up to 16.5 with a strong head wind but normally reads 14.- 14.5 with the van at anywhere from 85 to 95 kph.

Another question, the recommendation is that I replace the rear shockers only, at this stage the front appear O.K. This vehicle used to tow a 2 horse float every weekend before I bought it, so that could explain it, done 115000klms now, I did suspect the rears were not good from the trip we did to the N.T.
Looks like the air con compressor needs replacing as well so the budget is feeling the strain just at present.

DD

Originally Posted by gghaggis

Best to measure it - with the tyres you've got on, your trip computer could actually be pessimistic!

And of course, your D4 is carrying one or two accessories ........

Cheers,

Gordon

It does carry a bit...Including me. When I tow with the horse float I use the factory rims and tyres.

Brett....

Originally Posted by TerryO

Yeah but Tworags are sooky girly cars that get scared when you go off road. ...

I get a bit ....just a bit of flex in my Touareg!

A bit off topic ;-)

Brett....

I have a 1995 p38 range rover with air suspension and a 27ft caravan which is fully loaded both ball weight and overall

I've towed this van many 10s of thousands of kms

My car is rated for a 350kg ball weight and 3500kg towing. The same rubbish about wdh was said about my car

I cannot believe that lr would say you must not use a wdh.

A wdh would fix your stability problems

I can't imagine any reason you couldn't use one and I bet lets of people do. You might look into this further as to why you "can't". I was thinking of buying an lr4 but won't if you can't use a wdh.

Imagine a kids see-saw. Child sits on one end and the other end gets lifted into the air

Same with a car. Your rear axle is the pivot point and the tow bar is the child's seat on the end.

Your hitch is behind the rear axle. You put weight on a hitch and it levers weight OFF the front axle.

If you put 350kg on a hitch that is one metre behind the rear axle and the front axle is 3m forward of the rear axle you will take approx 120kg off the front axle. This will also go onto the rear axle

This reduced weight on the front axle will reduce traction on the front wheels and promote sway

Airbags will hold the car level but they won't change weight distribution

My caravan is scary without wdh and travels brilliantly with it

Some people may argue that airbags do the same job as a wdh. They don't and can't. This is an engineering fact. Airbags can make a car level. They cannot take weight off a rear axle and transfer it to the front.

Getting your tow ball as close to the rear axle as possible also helps a lot as does removing all slop/making it a tight fit

My hayman Reese tongue stuck out further than needed so we drilled a new pin hole so that it could be slid all the way in.

My thought - try it with a wdh and let us know.

Greg

Originally Posted by Ghind

...........I cannot believe that lr would say you must not use a wdh.

A wdh would fix your stability problems.......

Welcome, and an immensely brave first post.

It states very clearly in the handbook for both the D3 and D4 that a weight distribution device must not be used. The theory is that the onboard systems can detect trailer sway, and are able to correct it.

In the case of the OP of this thread, it turned out to be a suspension defect, a WDH would not have helped.

As for not buying a Discovery 4 on the basis that you can't use a WDH with it, that's like going to Dell and saying that you won't buy one of their PCs because you can't buy one with a 5.25" floppy drive.

Originally Posted by Ghind

I have a 1995 p38 range rover with air suspension and a 27ft caravan which is fully loaded both ball weight and overall

My thought - try it with a wdh and let us know.

Greg

Towing stability issues with a D3/D4 are almost always a problem with the van set-up. The next most common cause is the driver creating a sway by over correcting when the feel movement.

Suggesting that some use a WDH against recommendations is foolish. Below is a forum that welcomes poor advice head over there.

Caravaners Forum • Index page

Originally Posted by Glynhouse

WDH

A what now?

I don't do much towing of really heavy stuff so didn't know what that was, hopefully others find this video useful to explain what it does and more importantly how it works

[ame="http://www.youtube.com/watch?v=YDER3up7I_s"]Hensley Arrow Sway Control Hitch - YouTube[/ame]

PS: Now I still don't understand how it works, but see what it does - normally it takes this for me to learn: