AirBags

Quassie · Newbie

AirBags

Possum3 · Guru

Speak to suspension specialists like Pedders or similar.

Peter_n_Margaret · Guru

Air bags don't do the same thing as a WDH.
A WDH transfers weight from the tugs rear wheels to the front wheels to maintain better handling. Air bags simply raise the rear and can not transfer weight to the front.
The use of air bags on some suspensions is fraught with risk as the air bag forces are applied to an area of the chassis not designed to take them. Broken chassis can result.
Cheers,
Peter

Mickannie · Member

Hey Quassi
I would first check the weight of van and tug, you might be able to reload and balance things better and maybe adjust your ball height and get away with no extra help , we towed a 22 footer around Oz with no extras and never had a problem with our first van but did put a WDH on our second van for a few months but eventually took it off, found it was not needed and an added cost and weight (about 20 kgs)

Nevd · Senior Member

I can understand where you're coming from - they can be a pain in the butt at times, as well as extra weight in the hitch area. However, Jeep specify that use of a WDH is mandatory for towing over 2268 Kg. (Page 300 of the owners manual).

If your van weighs more and you don't have one, don't expect the insurance company to payout, for either the Jeep, or the van. It is the owner's responsibility to operate the vehicle within the limitations set by the manufacturer, no matter what others may tell you.

And as stated, airbags and a WDH are designed to do different things. Sorry to be a wet blanket.

Nev

Warren-Pat_01 · Guru

G'day Quassie,
Welcome to the forum, I trust the answers above have not put you off remaining in a useful, informative & sometimes humorous forum.

I have a Nissan Patrol & the first thing I did when we bought the van was to remove the springs that came with it for attaching to a WDH & have stored them in my garage. I bucked the advice given here many times & fitted airbags to the rear suspension. More advice I rejected was from the manufacturer of the airbags in the use of them. I don't want to break the rear of the car by putting up to 65psi in them! I may as well put a stump in the springs!

However Nevd said that Jeep requires you to use one - so that is what you must do. Some manufacturers tell the owner the opposite.

The Belmont Bear · Guru

Hi Quassie welcome to the forum, back in April I replaced my Pajero Sport with a 2018 MY Grand Cherokee Limited (without the air suspension). Like you I was interested in upgrading the rear suspension and possibly doing away with the WDH. On the previous vehicle I had airbags fitted by Pedders and I used them lightly inflated along with a WDH to take out what what felt to me like excessive bouncing over undulating road surfaces. Pedders told me they don't have any upgrades available for the Grand Cherokee and fitting airbags was my only option, they also said it was going to cost me more than the Pajero as the job was complicated and would take them longer to do. From memory the price they quoted me for ones with the protective sheaves was about double what I had paid previously so until I talk to other suspension specialists I have done as Jeep says in their manual and continued using the WDH. I towed our 21'6" / 2700kg van without one for a few KMs when I took the van to be serviced and to tell you the truth it didn't feel as stable , I personally wouldn't tow without using it on a trip.

Just as a matter of interest I asked the Jeep dealership during the 1000km service about upgrading the suspension and doing away with the WDH. They really had no idea what I was talking about until I showed them in the users handbook confuse . Being a new vehicle it is under warranty for the next 5 years so I don't want to take the risk of voiding it or my insurance.

Cheers

BB

-- Edited by The Belmont Bear on Wednesday 19th of September 2018 07:22:29 AM

mezza56 · Senior Member

Read this info it basically implies that even the smaller vans should be using a WDH if towing and airbags and stronger suspension do absolutely nothing except lift the bag of the car.

The amount of weight lifted off the front and imposed on the rear is a function of ball weight, rear overhang and wheelbase. The formula is:

(Rear Overhang ÷ Wheelbase) x Ballweight

So with a pretty modest van that only weighs 1,500 loaded, with a 10% ballweight, a tow vehicle with a 2750mm wheelbase and 1200mm overhang (rear axle centreline to centre of ball), the calculation is:

(1200/2750) x 150 = you are lifting 65 kg off the front and applying it to the rear in addition to the ballweight so 215 kg on the rear axle, suspension, wheel bearings, wheels and tyres. Thats going to affect handling, braking and steering and we haven't introduced any passengers of laguage as yet.

Or apply it to your a larger rig of say 2850 wheelbase, 1200mm overhang and 350 kg ballweight.

(1200/2850) x 350 = 147 kg off the front and a total of 497 on the rear, just short of half a tonne! While it might all be within the GVM of the vehicle, it may exceed the weight rating of the rear suspension and tyres? It might feel fine driving without a WDH but the reality is its not fine!

In both these cases, no amount of suspension changes, even replacing the springs with solid blocks, will not change this redistribution of weight. All it can do is hold up the same weight higher and maybe crack the chassis.

Quassie · Newbie

Hi Guys, that pretty much answers my question, I'll stick with the WDH reluctantly.
Thanks to all of you for your prompt replies. Much appreciated.

Quassie.

Blue River · Member

Hi we have just purchased new 2018 Grand Cherokee Laredo & ordered it with an adventure kit witch includes air bags & they are self leveling.We were told buy the caravan dealer at take over of the van we could use WDH because it would work against the self leveling setup in the Jeep. We towing around 3T fully loaded & Jeep seats & tows perfectly

Neville

-- Edited by Blue River on Wednesday 19th of September 2018 09:25:56 PM

iana · Guru

We tow a Jayco Silverline 24ft, with a BT50 traytop Ute. No weight distribution hitch, the rig sits nice and level, no problems. An SUV is a bit different though, load wise.

yobarr · Guru

iana wrote:
We tow a Jayco Silverline 24ft, with a BT50 traytop Ute. No weight distribution hitch, the rig sits nice and level, no problems. An SUV is a bit different though, load wise.

BT50 towing a 24 Jayco Silverline? Interesting was my first reaction,and I then wondered whether you have weighed ALL axles individually? Remember that your GCM is only 6000kg,from memory.Just because the vehicle sits nice and level in no way suggests that it is anywhere near safe,or legal.Just saying. Cheers

-- Edited by yobarr on Thursday 20th of September 2018 08:42:05 AM

Rusty W · Veteran Member

Hi Quassie, I have had a Laredo 2012 with steel springs. I fitted air bags to the rear as I did in my Pajero before it. The jeep comes with self levelling
rear shocks so air bags don't do much to hold the rear end up. Air bags reduce the porpoising over dips and hollows by stiffening the rear end. The air bags are fairly easy to install except the air line came out the bottom not good for off roading. Don't throw your WDH away.

I now have an Overland with air suspension and would prefer the Laredo for towing.

Regards Russell

Mickannie · Member

We two have a BT5O single cab/chassis with canopy, purchased new in 2015 and after the first 6 months ute suspension was sagging a little, Mazda make them a bit soft in the first place. Took it to springworks in Launceston and had them re-fire the old springs and fit extra leaf, result a lift of 25-30 mm and a stronger suspension.
Cost $430
Last year needed to tweak again, this time in Gympie so off to the local suspension place after looking at a few options put on the table the manager suggests that he just reverse the second stage leaf so that it works full time making things a bit stiffer, worked a treat cost $70.

Only stability issue we have had was a massive dip in the highway which had like a wave of asphalt pushed up in front of it running across our lane so no escaping it hit it at 90 ks not square on but left wheels then right wheels and van flicked one way then the other quite drastically, ESC kicked immediately and save the day.
Cheers Mick