wdh/airbags

mike g g · Senior Member

wdh/airbags

elliemike · Guru

I did a search on the Forum Quite a bit of stuff already on here available for perusal. in Search.

Used to have them on the X Trail briefly till I realised what the Tow hitch was actually attached to. I upgraded to another 4x4 Mitsubishi more suitable vehicle for what I was towing. But on the Xtrail they seemed to help in leveling a bit but The loading weight on the Hitch was still the same and worried me. That's why I sold it on. Never felt the need to Use WDH or Air bags since.

http://thegreynomads.activeboard.com/t34194482/air-bag-suspension-and-wdh/

http://thegreynomads.activeboard.com/t58207434/weight-distribution-or-air-bags/

Or just do a SEARCH "Air Bags"

-- Edited by elliemike on Friday 5th of February 2016 04:09:22 PM

PeterD · Guru

mike g g wrote:
I know we sometimes used to put a bit more pressure in the rear bags to assist with levelling ,,im thinking that this system must be doing a simular job as a wdh ,any thoughts would be appreciated.mike g.

This business of "making your rig look level" is only part of the solution. Then you hitch a van the rear of the tug takes a nose dive because of the weight placed on the rear axle. With the vehicles we use with vans there is a large overhang of the ball from the rear axle. This rear overhang amounts to around 50% of the wheelbase (with the Disco D11 it is 60%.) That means that the lever action of this large overhang will remove weight from the front axle, if your overhang is 50% the weight removed is 50% of the vans ball weight. Where does this weight go? It is transferred to the rear axle.

The result of this is the front of the tug rises because of the weight removed. The rear axle is severely overloaded as you have around 150% of the ball weight on it. This see-saws the tug severely and it looks crook and does not handle well because wrong load distribution. It is much the same as putting too much gravel in the rear of a ute and expecting it to handle OK.

Jacking up the rear of the vehicle with modified suspension does nothing for the weight distribution. It just makes it look "pretty." The only way you can correct the excessive transfer of weight is to use a weight distribution hitch. This transfers some of the ball weight to the front axle thus restoring its handling and reduces any tendency to of overloading the rear axle.

The following demonstration of WDH shows the action. Get out your pencil and paper and calculate the changes.

HR WDH display.jpg

Radar · Guru

Hi I have airbags but technically I was not in favour of going this way, it was a quick, temporary fix to problem of weak rear suspenion.

My plan is to replace all the suspension with after market by one of the leading brands to add a little ground clearance then add the caravan hoping it will sit better then standard, the air bags just that is only to help we run about 12/15psi in loaded with the Caravan and about 8psi around town.

The one thing I did notice after fitting the air bags was it sat better and I was happy with that for the time being. The ride in both situation was good.

Then I obtain a set of bars on our first trip out I stopped, release the pressure off them until they near dragging on the road as they were making the car ride so uncomfortable. Then the other problem rose was when we pulled off the road the bars dragged on the road.

I have tried them without preasure in the air bags with no joy.

Now run a medium set with 12psi and very happy but by all the experts should be on a path to tip my van over and break my chassis to boot.

So in answer to your question yes I have but run a meduim other no name brand of wdh bars and we are very happy.

1985 goss, 195 tow ball weight behind our Nissan.

Peter_n_Margaret · Guru

mike g g wrote:
Has anyone out there put airbags on there tow vehicle and stopped using a wdh......................

When you hitch a van to an overhung ball (well behind the rear axle), it adds weight to the rear axle and REMOVES weight from the front (steering) axle.

This can compromise both steering and braking.

The WDH transfers some of the weight from the rear axle back to the front axle to partially correct that problem.

Air bags CAN NOT do that. They simply jack the back up. Airbags and WDH do quite separate things.

Cheers,

Peter

Cupie · Guru

Peter_n_Margaret wrote:
mike g g wrote:
Has anyone out there put airbags on there tow vehicle and stopped using a wdh......................
When you hitch a van to an overhung ball (well behind the rear axle), it adds weight to the rear axle and REMOVES weight from the front (steering) axle.
This can compromise both steering and braking.
The WDH transfers some of the weight from the rear axle back to the front axle to partially correct that problem.

Air bags CAN NOT do that. They simply jack the back up. Airbags and WDH do quite separate things.

Cheers,
Peter

Spot on.

Gus1949 · Senior Member

I have a Ranger and a van with 280kg ball weight. When I fit the WDH on level ground and pull the bars up to the sixth link in the chains ( Hayman Reece say that's the maximum you should use) the bars don't apply much force to the front wheels and they are very easy to pull up and to insert the pins. Without the WDH the vehicle and van sit level. With them attached it reduces the distance from the top of the front wheels to the wheel arch by 10mm. I have towed the van with and without the WDH and honestly I can't tell the difference in terms of steering and baking. Is this the experience of other Ranger and BT50 owners?

Peter_n_Margaret · Guru

Gus1949 wrote:
I have towed the van with and without the WDH and honestly I can't tell the difference in terms of steering and baking.

You probably won't either, until you loose control.

Then it is too late.

Cheers,

Peter

Radar · Guru

Its a great Sunday morning.

-- Edited by Radar on Sunday 7th of February 2016 08:30:39 AM

hako · Guru

On my 10 year old 260,000km Ford Territory with original springs and shocks my rear has never bottomed out towing a 1300KG Avan Cruiser with a shepherds crook WDH. I know this to be a fact because when I fitted new rubber bumpers about 2 years ago I put some silverfrost on top of them so they would leave a witness mark if the springs ever bottomed.
The WDH in question cost $40 at a garage sale. New HD springs and shocks would have cost well over $1000 plus fitting. No contest really for me.

Good Luck.