Air bags on Utes , don't do it !

[Metters]

They are two very good links Al.  I have heard of that man but until now I have never come across anything that he has written.  It includes everything that I have been saying but I can not take any credit, I have picked it up from other sources over the years ever since I became aware of chassis bending and caravan instability.

He mentions stress on rear axles from ball weight.    I noticed in the story in 4X4 Australia that the men they interviewed  from Birdsville, Mt Dare and Alice Springs all agreed that trailers were a contributing problem.  One said  " A heavy ball weight has a significant effect on the chassis, as the 4WD pitches forward and back it accelerates the trailer ball mass up and down with a jerking motion.

“It’s the acceleration of this mass that will contribute significantly to bending and cracking of the chassis,” he continued. “A longer hitch or tow bar, as fitted to some utes with a long tray (itself an issue), compounds this problem of shock loading to the chassis."

It is that word "mass" again.  Mass [material] in motion is the real culprit here and the sooner all trailer owners understand it the better.

If they did then more pressure could be put on trailer builders to lift their game. 

Car manufactures have been right into vehicle dynamics and suspension design since the late 1930s.  Most trailers today look like they could have been designed in the '30s.

In the caravan magazine article titled "Vehicle Dynamics" by Collyn Rivers, he said trailer ball weights are absurdly too high and testing has shown that anywhere from 2% to 20% makes little if any difference.  He then added he suspects the recommended ball weight is what it turned out to be when they made the first one.

This is coming from a man who has spent the last twenty years studying all caravan and trailer stability research around the world and is about to release a book on it.

[4wd26]

you can see that the bump stop has contacted the top plate, airbags just makes this "stop" of momentum earlier, but if poorly loaded (you don't have to be overloaded) and you continue to hit the bump stops "hard" something will eventually fatigue, and if a large enough force is acted it can be the first such hit.


this one hit a washout in the road- you never get the whole story from one picture

Our trailer tyre which blew at the same time our companions chassis bent

[Darcy7]

Id be heartbroken if that was my new pride and joy


Sent from my iPhone using Tapatalk

[hempo]

Great info there guys.

Sorry for going off track, however Spada, did your neighbour get his replacement BT?  I am curious as to why you went to the trouble of taking all the old accessories off, if he was getting a new BT he should also be getting all new accessories at the same time.  As you stated New for Old replacement. 

Cheers

[Spada]

Great info there guys.

Sorry for going off track, however Spada, did your neighbour get his replacement BT?  I am curious as to why you went to the trouble of taking all the old accessories off, if he was getting a new BT he should also be getting all new accessories at the same time.  As you stated New for Old replacement. 

Cheers

Still waiting, but I see it parked out front today minus bull bar, so it must be about to go.

All the fruit had to be removed cause it wasn't listed as inclusions on the policy, so they wouldn't replace what wasn't insured.

[jr]

Dual cab Navarra bent chassis at work this week, same story, big load in steel tray
Hardy say it had worked hard, mostly highway use
Yes it had airbags but that was to stop saggy rear.

[KingBilly]

Dual cab Navarra bent chassis at work this week, same story, big load in steel tray
Hardy say it had worked hard, mostly highway use
Yes it had airbags but that was to stop saggy rear.

If it had a saggy rear, it was either over loaded or had incorrect rear suspension.

KB

[scarpsD40]

Dual cab Navarra bent chassis at work this week, same story, big load in steel tray

[Metters]

Dual cab Navarra bent chassis at work this week, same story, big load in steel tray

I saw another one three days ago going into a Bunnings car park.  It was an early 2000s dual cab 2wd Hilux.  It had an extra long tray with a lot of heavy looking tools in it.  I could not stop and see if the suspension had bags or not.

[Steffo1]

Not sure about air bags?

[Footy Shorts Shane]

Not sure about air bags?

Is the genny to run the AC

[tk421]

Not sure about air bags?

not sure about the rampover either...

[callmejoe]

Came across a newish triton today. Another sad end for a holiday maker.

Towing a smallish off rd camper. Air bags fitted. Cannot comment on there load as i saw the end result.
Bent both rails on each sides on the rear top bracket arm.

Joe.

[Metters]

Came across a newish triton today. Another sad end for a holiday maker.

Unfortunately I can't see this stopping for a very long time.  I would love to see four or five manufacturers of air bags and stiffer aftermarket suspensions on a TV show like Q & A explaining how their products can support the far end of the chassis on an overloaded car and stop it flexing up and down.   

[tk421]

Unfortunately I can't see this stopping for a very long time.  I would love to see four or five manufacturers of air bags and stiffer aftermarket suspensions on a TV show like Q & A explaining how their products can support the far end of the chassis on an overloaded car and stop it flexing up and down.

Easy, they'd just say our products are designed to work within the manufacturer's limits. We cannot be held responsible should you choose to exceed them. I don't think any of them state they'll allow you to overload your vehicle.

I can't see how any of them can be held responsible should the operator choose to overload their vehicle

[jr]

"If it had a saggy rear, it was either over loaded or had incorrect rear suspension"
Yep thats what ive been saying, maybe not just overloaded but poorly distributed.

Rough numbers but concept is there.
Have a look at normal dual cab, 1000kg payload,
5 seats@ 80 kg each, = 400kg - this capacity cant be moved out of the cab.
Fuel + other stuff, 150kg
Give up another 100kg for steel tray........leaves 350 kg payload in the tray max. AND thats if the tray is same length as ute tub, most are much longer. (50kg at the back of a tray could place 3 or 4x the load on the chassis at the axle)
plenty think the 1000kg can be put in the tray

Springs or airbags have little to do with it.

Change to a single cab, and you then can have 600+ kg in tray - a lot more.

[Spada]

"If it had a saggy rear, it was either over loaded or had incorrect rear suspension"
Yep thats what ive been saying, maybe not just overloaded but poorly distributed.

Rough numbers but concept is there.
Have a look at normal dual cab, 1000kg payload,
5 seats@ 80 kg each, = 400kg - this capacity cant be moved out of the cab.
Fuel + other stuff, 150kg
Give up another 100kg for steel tray........leaves 350 kg payload in the tray max. AND thats if the tray is same length as ute tub, most are much longer. (50kg at the back of a tray could place 3 or 4x the load on the chassis at the axle)
plenty think the 1000kg can be put in the tray

Springs or airbags have little to do with it.

don't forget 150kg is on the tow-bar, + another 30 odd for a duel battery, + a bit more for the bullbar, got a winch on that ? there's another 30, then add 40 for your Engle full of beer, not to mention another 30 odd for your fancy drop-down fridge slide ? have you got a canopy on that tray ? what about a draw system,  have you got any recovery gear ?

So about all you can pack is a box of tissues and a change of jocks (although you could substitute one for the other if your worried about the extra weight)

[Steffo1]

So about all you can pack is a box of tissues and a change of jocks (although you could substitute one for the other if your worried about the extra weight)

Might end up with green "Skidmarks"?

[Metters]

I can't see how any of them can be held responsible should the operator choose to overload their vehicle

The Triton at the top of the list of photos that Spada posted on page 2 of this discussion was not overloaded.  The owner had carefully watched the weight of the things he was putting into it and had weighbridge certificates showing it was about 200 kg under GVM.   He thought he had done the right thing and was blaming the quality of the car for the bent chassis.

It is easy to understand why so many owners have thought everything was ok.  The net forums are full of wonderful advice like stock suspensions are crap and  a set of air bags or brand X stiffer suspension will fix everything.   You then have the magazines and their DVDs plus their advertisers claims saying the same thing.   Even the bent chassis story in 4x4 Australia contains a rather dubious piece of advice.  The bloke from ARB said air bags are just a band aid solution and “ until they upgrade to some well sorted aftermarket springs and shocks, they’ll continue to have issues”.

As I said before I would like him to explain how his well sorted springs and shocks support the far end of the car.  Only a spring between the end of the car and the road surface can do that and I haven’t seen any of those on the market yet.

You then have products like dual wheel carriers.  Inexperienced owners see products like this and think it is fine to hang two 35 kg wheels plus the weight of the carrier off the back of their car then put 130 kg on the tow ball.  Their ball weight is around half the maximum so that should be ok and the carrier would not be on the market if it was threat to the car's reliability.   

Maybe the solution would be for the manufacturers of these aftermarket suspension systems and other accessories to follow the example set by medicine manufacturers and list what their product will cure and what, if any, side effects it can cause.  I suppose if they did that though, people will load their cars correctly and not need their products.

[4wd26]

The Triton at the top of the list of photos that Spada posted on page 2 of this discussion was not overloaded.  The owner had carefully watched the weight of the things he was putting into it and had weighbridge certificates showing it was about 200 kg under GVM.   He thought he had done the right thing and was blaming the quality of the car for the bent chassis.

It is easy to understand why so many owners have thought everything was ok.  The net forums are full of wonderful advice like stock suspensions are crap and  a set of air bags or brand X stiffer suspension will fix everything.   You then have the magazines and their DVDs plus their advertisers claims saying the same thing.   Even the bent chassis story in 4x4 Australia contains a rather dubious piece of advice.  The bloke from ARB said air bags are just a band aid solution and “ until they upgrade to some well sorted aftermarket springs and shocks, they’ll continue to have issues”.

As I said before I would like him to explain how his well sorted springs and shocks support the far end of the car.  Only a spring between the end of the car and the road surface can do that and I haven’t seen any of those on the market yet.

You then have products like dual wheel carriers.  Inexperienced owners see products like this and think it is fine to hang two 35 kg wheels plus the weight of the carrier off the back of their car then put 130 kg on the tow ball.  Their ball weight is around half the maximum so that should be ok and the carrier would not be on the market if it was threat to the car's reliability.   

Maybe the solution would be for the manufacturers of these aftermarket suspension systems and other accessories to follow the example set by medicine manufacturers and list what their product will cure and what, if any, side effects it can cause.  I suppose if they did that though, people will load their cars correctly and not need their products.

I can guarantee that that triton was overloaded- regardless of the weighbridge certificate, the fact he watched his load and the rest of his arguments
there is no way that that particular vehicle would have been under the rear axle load limit for the vehicle, even if under the GVM

as mentioned earlier a lot of weight is supposed to be distributed through the cabin area

that vehicle had twin tyre carriers, an aftermarket fuel tank behind the rear axle and the ball weight
that vehicle had also lengthened the tow hitch so that the trailer hitch could clear the rear tyre carriers.

basically everything that could have been done to make the pivot on the rear (as far rear) as possible was done

its worth noting in this discussion as the GVM is also not the whole picture
there is how the load is distributed. 

[tk421]

The Triton at the top of the list of photos that Spada posted on page 2 of this discussion was not overloaded.  The owner had carefully watched the weight of the things he was putting into it and had weighbridge certificates showing it was about 200 kg under GVM.   He thought he had done the right thing and was blaming the quality of the car for the bent chassis.

It is easy to understand why so many owners have thought everything was ok.  The net forums are full of wonderful advice like stock suspensions are crap and  a set of air bags or brand X stiffer suspension will fix everything.   You then have the magazines and their DVDs plus their advertisers claims saying the same thing.   Even the bent chassis story in 4x4 Australia contains a rather dubious piece of advice.  The bloke from ARB said air bags are just a band aid solution and “ until they upgrade to some well sorted aftermarket springs and shocks, they’ll continue to have issues”.

As I said before I would like him to explain how his well sorted springs and shocks support the far end of the car.  Only a spring between the end of the car and the road surface can do that and I haven’t seen any of those on the market yet.

You then have products like dual wheel carriers.  Inexperienced owners see products like this and think it is fine to hang two 35 kg wheels plus the weight of the carrier off the back of their car then put 130 kg on the tow ball.  Their ball weight is around half the maximum so that should be ok and the carrier would not be on the market if it was threat to the car's reliability.   

Maybe the solution would be for the manufacturers of these aftermarket suspension systems and other accessories to follow the example set by medicine manufacturers and list what their product will cure and what, if any, side effects it can cause.  I suppose if they did that though, people will load their cars correctly and not need their products.

Mate - I was responding to your statement (highlighted):

I would love to see four or five manufacturers of air bags and stiffer aftermarket suspensions on a TV show like Q & A explaining how their products can support the far end of the chassis on an overloaded car and stop it flexing up and down.

My response still stands:

 

I can't see how any of them can be held responsible should the operator choose to overload their vehicle

[Brij]

I can guarantee that that triton was overloaded- regardless of the weighbridge certificate, the fact he watched his load and the rest of his arguments
there is no way that that particular vehicle would have been under the rear axle load limit for the vehicle, even if under the GVM

as mentioned earlier a lot of weight is supposed to be distributed through the cabin area

that vehicle had twin tyre carriers, an aftermarket fuel tank behind the rear axle and the ball weight
that vehicle had also lengthened the tow hitch so that the trailer hitch could clear the rear tyre carriers.

basically everything that could have been done to make the pivot on the rear (as far rear) as possible was done

its worth noting in this discussion as the GVM is also not the whole picture
there is how the load is distributed. 

What he said 

GVM, GCM is only a part of the picture. Maximum axle weights are very often not taken into consideration.

I weighed a twin cab '79 series with a caravan a couple of years ago. The owner had done a great job. All the mod cons, ARB, TJM and what ever other brands as well. A beautiful aluminium canopy. Tinny and trailer or the top. Very well made.

And he had the GVM upgrade as well because he was worried it was going to be "heavy".

Had a caravan attached, which was also weighed. 220kg ball weight.

Vehicle weights - actual gross weight 4040kg (upgraded GVM 3780kg) 260kg over
                            actual front axle weight 1280kg (rated at 1480kg) 200kg UNDER
                            actual rear axle weight 2740kg (rated at 2300kg) 440kg OVER.

So even though the total weight was 260kg over the upgraded GVM, the rear axle was 440kg over. Near enough to half a tonne. Or 1/4 of the total weigh OVER.

Bringing the total weight back to the rated GVM (ditching the caravan) would not fix all the axle weight issue. (In hindsight I should of reweighed the axles again with the caravan disconnected. )

I can give you examples of the heavy vehicle industry where trailer manufacturers have spruiked of their trailers being able to carry X tonnes, which they can, except when hooked up to a truck the rear axle is always overloaded and the front axle is always underloaded. 

Peter

[Bird]

Simple.. to stop all the bitching don't buy a ****ing ute..

Thread lock time.

[scarpsD40]

Simple.. to stop all the bitching don't buy a ****ing ute..

Thread lock time.

only mods can lock threads. Aren't you one yet?

[Bird]

only mods can lock threads. Aren't you one yet?

practicing...