air bags

Mick

You are best with both - the Polyairs generally keep it level under load and stiffen up the suspension with a load on the back. But you need the WDH to get some of that weight on to the front wheels to keep steering control and prevent being one of those spin outs coming down hill.

With a relatively small van you might get a good feeling with just the Polyairs, but you may never find out till the emergency. If you can afford only one, the WDH is the one to get.

You don't need a huge one - the Hayman Reese Mini Hitch at the bottom of this page ( Site Link )
is for 82 kg ball load and your load must be pretty close to that.

Max

Hi Mickpaj,

I had a 13'6" Windsor Rapid and towed it with a GU patrol and prior to that an 80 series cruiser.

I fitted airbags to the GU and reckon it was the best thing I did. For non-towing, simply let them down and have a normal ride around town and when towing, pump then up and easily handle the weight.

On the cruiser i fitted heavy duty springs in the rear. While it was great when towing, the ride was too stiff when driving around town with no load, hence why i tried the airbags when I got the GU.

As for a WDH, I never had any sort of problems towing and from personal experience with this particular van would recommend the airbags as the first option. But bear in mind I had a winch, steel roo bar and dual batteries in both vehicles hence extra weight on the front end compared to a "standard" setup.

Cheers

Captain

Mick,
I use both. I started with the WDH and then added the Polyair bags on my 80 series. I'm happy with the result.

Toolman

Hi Mick,

we also have both, towing a 14'6'' Windsor Rapid with '99 Jackaroo Diesel. The airbags really cure that drag-arres effect of scraping on the floor, which you might get if your vehicle suspension is biased towards comfort ride rather than truck like. The purpose of the WDH is to transfer some of the ball weight onto the front wheels of the tow vehicle for stability, which is subtly different.

We recently did a couple of hundred kms through the forest roads of SW WA and not once felt the rig was unstable at speeds up to 100 km/h.

I also would recommend both. The ball weight should be 5 -10 % of the van weight, but this weight on the tow vehicle will tend to lift weight off the front wheels of the tow vehicle. The air bags may bring the tow vehicle back to level, but as stated above, they will not transfer any weight back onto the front wheels of the tow vehicle.

The actual ball weight depends a lot on the internal layout of the caravan - our 14'6" model is not necessarily any greater than the 13'6" model, plus how it is loaded. We have the 250 kg HR WDH model, which can be set up to transfer various load by altering the angle of the ball and by varying the number of links in the chain. Selecting the correct WDH starts with the ball weight which should be on the small plate attached to the A frame, but this will change as you load up your van. I think some manufacturers just stamp on a 'standard figure' and some actually weigh each van. Obviously the latter is preferred, plus checking at a weighbridge when fully loaded.

Air bags from truck springs in the US, their web address posted elsewhere several times before.

Red-one.

I'd be inclined to replace your springs with something a bit stiffer, maybe progressive rate. 10 year old springs are bound to be a bit soft and your vehicle will ride heaps better with new ones, both when towing and not. How old are your shockies? Maybe change them at the same time.

You don't HAVE to go for raised springs, you can get heavy duty in standard height if you really want....

I replaced the springs in my NM as a first step in curing the same sagging problem when towing and have found I don't need anything else, it rides nice and level now.

I have a 17ft van and 3.0 litre patrol,numerous spring swaps and polyair combinations over past few years.
I have now bit the bullet and removed the coils completely and fitted an airbag man system.
For the shocks and bag kit it cost $1800,I now have complete adjustability and control over the rear suspension.
I still use the levelling bars on the van just to put some weight back on the steering.
However the most economical way for you is original soft springs with polyairs.
Truck springs USA are the best buy at half the Aust price.
Regards

Mick

Just try the WDH first. You should have WDH to put the weight back on your front wheels if only to restore the braking performance - particularly if you do not have ABS. I have seen several near misses when tow vehicles have had front wheel lock up on roads with spilt sand on them or wet conditions (yes it will rain again one day.)

If you fit the WDH first you may find that you do not need the rear suspension modifications - which will be dearer than the WDH.

PeterD