Caravan towing bouncy ride

[hotqld]

Hi
We are towing a caravan 2800ATM 350kg ball weight.
When the road gets a little rough dips in the road the caravan bounces on the tow ball and makes the jeep bounce quite severely.

What suggested improvements is there we can make?
I am looking at the air lift 1000 in the rear springs, are their other options out there?
we do have HR WDH.
2007 WH Grand Cherookee 3 ltr CRD.
We dont do any off roading.

[hicko1]

hey hotqld, we will be taking our 06 WH up to top of oz in june for the winter, we updated from 03 commodore wagon everyone said to use wdh's which I did , but everyone said we don't need them with jeep and tandem van 18'6", I am waiting like you to see the answer to your question, also sorry I not got your answers Regards Hicko

[hotqld]

Originally Posted by hicko1

hey hotqld, we will be taking our 06 WH up to top of oz in june for the winter, we updated from 03 commodore wagon everyone said to use wdh's which I did , but everyone said we don't need them with jeep and tandem van 18'6", I am waiting like you to see the answer to your question, also sorry I not got your answers Regards Hicko

We noticed a definate improvment with stability when WDH was installed.

[pmac]

First thing I would do is get some heavy duty springs on the rear. I got mine from EBAY for about $300 for a set of 4. Kings I think.

Many in the US swear by OME, and I would imagine it may even be cheaper to ship OME springs from the US than buy them locally - go figure. Kolak would be the place to go.

Also, CRDSTU will be able to supply you with a specific set up to suit your needs.

[Clarky]

Hi hotqld

Although my van is lighter then yours (2000kg ATM & ball weight 200kg) I experienced a similar issue on the development roads in outback Qld last year.
I found that if I removed the WDH the “Bounce” was greatly reduced.

I like the WDH as I feel it returns some of the positive feel to the steering and reduces sway when a truck goes past so I refitted the hitch but reduced tension on the chains.

I remember reading somewhere that each full link after the tension is placed on the rod(Long arm) displaces approximately 20kg.
As for air bags, if you are running standard suspension I would say yes, use the air bags to level the Jeep and the WDH to return steering control.

I have had heavy duty springs fitted (CRDSTU made by King Springs) and the rear end sag is limited (about an inch) and it sits level.

I would also check your tyre air pressures as a lot of people over inflate the tyres on there grand, factory recommended pressures are only 33psi.
When towing I run 33psi in the front and 35psi in the rear. After an hour on the road I re-checked the pressures and the front where 36psi and the rear where 39psi.
I used the on-board tyre pressure system to check the pressures.

If your pressures are to low the psi increase would be greater then 4 psi (which is considered normal) and you would need to add more air.
Over inflation gives a firmer ride and wears out the centre of the tyres prematurely.
If you choose to replace the springs do both the front and the rear, you won't be sorry as the handling is greatly improved over standard.

I am not saying that this is the solution to your issue but it helped for me.

Ps
My hand book says the max tongue weight is 327kg. Is yours a Hayman Rease towbar or factory?

Dave

[drj33p]

That's to much ball weight for a 2.8t van for starters, should be about 8% or around 230kg's.

My van is 3T GTM and ball is around 220-240kg's depending on load.

My Grand has aux. fuel tank with rear tyre carrier, in the back when traveling there is a car fridge, tool box, all the drinks and more and i will get a little bounce sometimes but nothing to worry about.

I have HD springs and shocks (OME) and have just fitted Polyairs to the rear (but thats more for my camper as i cant use a WDH with it).

I would go back to the start and look at how the van is loaded and get the ball weight down.

[bodgie]

I tend to agree with drj33p, I'd be checking the weights of the van and the way it is loaded. I wouldn't be spending money on upgrading vehicle suspesion etc until you sorted out the caravan loading and weights.

Can you tell us how the GC is loaded when on a trip as this could contribute to the behaviour you have documented.

Is the 350kg ball weight the manufacturer supplied weight or is this a measured weight with the normal load?

This document may be helpful, I'd pay particular attention to the GCM section, I'd also suggest you check to see what the GCM for your GC is as you may be over the specified value.

http://rvmaa.com.au/PDF/G-Caravan%20...&%20Masses.pdf

I'm of the opinion you need keep an eye on all of the weights to make sure you don't have any insurance issues. Insurance companies will look for a way not to pay, and if a vehicle is overloaded and is deemed to be a contributing factor to an accident you may not receive any money.

HTH,

Jason