Dual Cab Chassis, Broken...Baw Haw..Sob..

[Dean Anderson]

Setup was fine. load was below.......Just a matter of the driver not seeing a series of bumps that just happened to make the weight on the rear of the car and towball weight go up and down a couple times at the same time. This I assume cause my suspension to max out......something had to give...

I think it's an inertia issue not so much a weight issue (even though both are linked). Sort of like putting one ton on a one ton ute....Not a problem...Dropping that ton onto your ute from a second storey buildings not quiet the same thing.

 

[achjimmy]

Dean where did it actually bend?

 

[achjimmy]

you have totally miss under stood me, my apologies for not being clearer

a lot of people (including "informed" motoring journalists) have not the slightest idea the function of the Air Bags fitted to suspensions
they are to
1) primarily to assist the springs in their function of supporting weight
2) assist in the down wards force exerted on said springs
3) help in maintaining the spring efficiency when under load
4) extend the life of the spring doing its job

now, take a Land Cruiser ute - 1000kg pay load
it will carry that 1000kg load for a long time, but over time the springs will weaken and sag
if you add Air Bags to the springs, it will still only carry 1000kgs, but it will extend the life of the spring

now, some air bags are quoted as being good for 200kgs & 400 kgs (that I have seen)
but it does not mean that you can now carry 1200kgs or even 1400kgs in your ute

as soon as the chassis cracks / breaks / snaps / whatever, the first port of call is............

Ahh, you have air bags, thats why XYZ happened
sorry, no thats NOT why XYZ happened, XYZ happened because it was not manufactured correctly in the first place

would it have happened without the air bags being there........???
possibly
maybe
probably

(metal fatigue in manufacturing is not that un-common, but a "SWL" Safe Working Load is worked out on Mechanical stress)
but that is an entirely different discussion

I remember the great debate in the late 70's and early 80's about putting turbo's on diesel engines, how the stress them too much, and blow motors
currently, there is also the push that LPG is bad for engines because they burn at 110% - there for they must run hotter - which is crap

anyway.....

to cut a long story longer - @Holden_man I was not having a go at you - merely poor journalism

Col the biggest issue with airbags on leaf sprung utes is they are causing a force /load whatever at a point on the chassis not designed to take it.

 

[achjimmy]

Dean if you dont want to repair your chasis by strengthening i fear just straightening it will leave with a weakened chasis or are you happy for the insurance to write it off.

 

[Dean Anderson]

Bent either side of the bump stop. The shockies alternate one facing forward one facing backwards. Bends were the opposite side. to the shockies so not symmetrical.

 

[Dean Anderson]

One thing about airbags......If your bumpstop is going to slam into your chassis cause your springs aren't heavy enough there's no difference to having airbags, same thing happens... Its only if the length of travel of your springs is reduced that they could be a problem.

This gives me an idea............maybe airbag companies should place a blowout valve in them so that in extreme cases of travel not just heavy payload the chassis could be saved..........They could even have different blowout forces for different model/strength cars.........Patent it.............What a money maker...........

 

[achjimmy]

Was trying to google to see if silverados or F trucks bend chassis with airbags and came across this interesting.

I have a BT50 dual cab and had air bags fitted and bent my chassis directly over the airbags. Mazda do not recommend air bags and I personally spoke to the "Airbag Man" (at Brendale Qld) engineer who told me that they DO NOT recommend air bags for the ranger /bt50 unless the chassis has been specifically strengthened. I spent 6 months fighting my insurance company until they coughed up the $$ for the chassis repair (I have their engineers report stating IN WRITING the same advice about airbags and BT50 / ranger as the Airbag Man told them the same thing). I now have a L plates welded onto the outside of each chassis rail running from the rear of the chassis to about 1/2 way along the chassis (about where the front and back passenger doors meet). I got rid of the airbags and fitted ARB Heavy Duty Leaf Springs. As soon as you modify the chassis you have to have it approved by an engineer and plates accordingly. If you search this forum for BT50 bent chassi rails you'll find my thread on what happened to me. Cheers. PS my repair was done by Creative Conversions at Brendale Qld, they did a good job.

http://4wdaction.com.au/forum/viewtopic.php?f=118&t=100809

 

[achjimmy]

One thing about airbags......If your bumpstop is going to slam into your chassis cause your springs aren't heavy enough there's no difference to having airbags, same thing happens... Its only if the length of travel of your springs is reduced that they could be a problem.

This gives me an idea............maybe airbag companies should place a blowout valve in them so that in extreme cases of travel not just heavy payload the chassis could be saved..........They could even have different blowout forces for different model/strength cars.........Patent it.............What a money maker...........

Somewhere recently I read about a BT that bent the chassis and it did not have airbags. I think they just expasterate it because the mere act of fitting airbags is to assist with the overload people are doing.

 

[achjimmy]

I've said this before. Trucks and utes have been bending chassis for ever. My dad worked for a chassis specialist in the 50s primarily fish plating and repairing bent truck chasis caused from overloading. The famous Holden "one tonner" was a beuty at bending chassis. The difference was nobody was all up tight about it back then they just fixed and got on with it. Today it's got to be engineered, Anaylised and accessed to the living day lights.

Buy a ute load it sensibly and you'll probably be okay! If you wanna push the boundaries then look at modifying it sensibly.

 

[Dean Anderson]

Photos

 

[achjimmy]

Och good luck sorting mate.

 

[davemc]

double ouch hope insurance covers everything and is done quickly for you

 

[Matty4]

Part of the problem also with most, if not all, current dual cab utes is the distance from the centre of the rear axle to the centre of the towball is usually a lot further than a traditional 4WD wagon. I would imagine it would be in the vicinity of 300-400mm further away, placing more strain and weight onto components, like suspension mounts etc.,

I've even seen some of those with AM trays that then require a longer towball tongue that standard, just to clear the back of the tray.

Hope you sort it out @Dean Anderson

 

[Tone]

Part of the problem also with most, if not all, current dual cab utes is the distance from the centre of the rear axle to the centre of the towball is usually a lot further than a traditional 4WD wagon. I would imagine it would be in the vicinity of 300-400mm further away, placing more strain and weight onto components, like suspension mounts etc.,

I've even seen some of those with AM trays that then require a longer towball tongue that standard, just to clear the back of the tray.

Hope you sort it out @Dean Anderson

Agree with you, I can't work out why out ML triton has a ball weight of 250kg and the MN has 300kg and towbar is 300mm ish further back.

 

[Dean Anderson]

Had to move my gas bottles on the van back 100mm to allow the tray to miss them when turning tight. They'd miss on flat ground but wasn't sure about on a v type slope. The corner of the tray used to be about 20mm from hitting the bottles. Tray was as supplied by Ford.

 

[Bushman]

Check out this brand new chopped LC200 !

Not trying to be arrogant but the difference between a standard 200 chassis and the current crop of utes is stupidly different and then the guy went and done this for a tray. Awesome and I reckon if I was decking out a dual cab I go a tray and try and do the same thing. Doubt she'll break if dropped!

View attachment 36126 View attachment 36127 View attachment 36128

I don't get it ! why do that to a perfectly good 200, if they want a tray back why not just buy one, is it a status thing or just have to be different, guess some people have to much $$$ to chuck around. Sorry :focus:

 

[achjimmy]

I don't get it ! why do that to a perfectly good 200, if they want a tray back why not just buy one, is it a status thing or just have to be different, guess some people have to much $$$ to chuck around. Sorry :focus:

Cause you can't get a V8 automatic single or dual cab coil sprung ute on the market today. If I had $$$ I do it in a heartbeat

 

[MDS69]

Cause you can't get a V8 automatic single or dual cab coil sprung ute on the market today. If I had $$$ I do it in a heartbeat

and also this now has two turbos as opposed to one and the same track on the front and rear axles with a better interior

 

[macca]

Any update Dean on your car?

 

[Dean Anderson]

I'll post the status as it goes...............
I'm insured with Suncorp if anyone is interested.

I'm remote (400km from Toowoomba).
Report the incident Friday. Told that I would be contacted mid next week by a rep...It happened on the Thursday arvo.

Told to go to the local panel beater that can't align a chassis and he says he can't do the job. I ring Suncorp again from home to fill them in and they send me back to the local panel beater to take photos and quote the job (he can only replace chassis cause he doesn't have the required equipment to get it back to spec).....

Now I'm waiting up to 6 days (as stated by Suncorp) for an assessor to decide what to do.