Suspension upgrade

Gus1949 · Senior Member

Suspension upgrade

travelyounger · Guru

Heavy duty springs in front and extra leaves in rear and heavy duty shocks and don't recommend using airbags on leaf spring suspension also a wdh helps to stabilize the ride on those undulating and bouncy .outback highways if you don't have one .There are kits available at most aftermarket suspension companies which upgrade your gvm and gcm but check your state regulations as all are different.
Cheers

Greg 1 · Guru

I have pretty much the same set up but with WDH attached. My Ranger PX1 has standard shocks and springs. Don't get any excessive porpoising than what I would normally expect with a van on the back. In fact the Ranger is particularly good in the ride department. My van is just on 3 tonne and ball weight at last weigh was 308kgs. Try a WDH. Just don't have it too tightly tensioned. Its not a load levelling device. And try not to listen to the anti WDH brigade. They work. I have been using one since the mid 70's.

outlaw40 · Guru

Agree with above if your not using wdh tten try that first . Stay well away from airbags on a leaf spring suspension as tgey have the potential to bend chassis .

Radar · Guru

6 years now have had air bags on our of the Nissan Navara crew cab ute with leaf springs, at first they did what was needed but have now spent good money on a full suspension make over, really the best money spent as most, if not all cars, utes are not designed to tow heavy caravans.

Our caravan comes in around 2800 with 270 kilos on the ball and a gvw of 5 500 kilos.

Airbags have about 12psi in them.

For the most a very comfortable ute with auto transmission.

Greg 1 · Guru

I have used airbags on a Pajero which is coil springs and they are good for that. I would not use them on a leaf sprung dual cab. The fact that you have had them on your Navara without issue just means that you have not met the right set of circumstances yet. There is plenty of evidence around to show the consequences of fitting them to leaf sprung vehicles to be a very convincing argument not to do it. Safer to get an uprated spring pack than risk a bent chassis.

Radar · Guru

Greg 1 wrote:
I have used airbags on a Pajero which is coil springs and they are good for that. I would not use them on a leaf sprung dual cab. The fact that you have had them on your Navara without issue just means that you have not met the right set of circumstances yet. There is plenty of evidence around to show the consequences of fitting them to leaf sprung vehicles to be a very convincing argument not to do it. Safer to get an uprated spring pack than risk a bent chassis.

Without getting into a writing war of words about leaf sprung crew cab utes, yes I have witnessed bending chassic and I have also seen broken chassis on un airbagged utes, no car maker is exempt from having cars with broken chassis.

I have now had 6 years of use of our airbags which is my experience with our crew cab before that I ran them in a Landrover Discovery series 2 for about 18 months very satisfactorily.

You have no experience only on a coil sprung Pajero, I think it time for you to back off until you gain real experince.

Aus-Kiwi · Guru

Firmer springs REQUIRES firmer shocks !!

iana · Guru

I have a Mazda BT50, cousin of your vehicle, have up-graded the rear springs only with heavier shocks, towed a heavy van with a ball weight the same as yours, no WDH and no problems for 30,000km.

Wanda · Guru

Mazda BT50 3.2lt towing 2900kg with a ball weight around 280kg, Ironman helper spring($130) on the rear springs the rest standard suspension. We only had the WDH and it towed very well, the rear end down a little bit but not too bad at all with very very little porpoising and only on certain undulating roads.
WDH cost from memory around $5-600, suspension upgrade probably in the range $2-3000.
I was happy with our setup, others prefer suspensin upgrades, both seem to work.
cheers
ian

outlaw40 · Guru

Radar your last statement is like a smoker saying i smoke and im not dead so they cant be harmful . You dont need to use airbags on a leaf spring suspension and bend a chassis to know they can and do bend them . A quick google search may enlighten you before you have a go at anyone else .

yobarr · Guru

outlaw40 wrote:
Radar your last statement is like a smoker saying i smoke and im not dead so they cant be harmful . You dont need to use airbags on a leaf spring suspension and bend a chassis to know they can and do bend them . A quick google search may enlighten you before you have a go at anyone else .

As Steve rightly says,a quick Google search will reveal that airbags cause point loading at a point in the chassis that was never designed to carry weight.This is a major cause of bent chassis.Airbags on a coil-sprung vehicle are a totally different kettle of fish altogether,with the load being carried in an area designed for such. Fitting airbags to a leaf-sprung vehicle is asking for trouble unless those airbags are only inflated to a level where they do little anyway.Simple physics again.Cheers

Greg 1 · Guru

It is true, Radar, that I have not fitted them to a leaf sprung dual cab so have not experienced them on that style of suspension or suffered the consequences as a result. However, even before I fitted them to the Paj, I did a lot of research on the subject and there is overwhelming evidence that says fitting them to a leaf sprung vehicle is not a good idea, particularly dual cab utes. Given that evidence I am not about to go and risk damage to my vehicle just to prove a point. Others have already done that for me.

yobarr · Guru

Greg 1 wrote:
It is true, Radar, that I have not fitted them to a leaf sprung dual cab so have not experienced them on that style of suspension or suffered the consequences as a result. However, even before I fitted them to the Paj, I did a lot of research on the subject and there is overwhelming evidence that says fitting them to a leaf sprung vehicle is not a good idea, particularly dual cab utes. Given that evidence I am not about to go and risk damage to my vehicle just to prove a point. Others have already done that for me.

Greg 1 · Guru

And there's a lot more pictures like that and not just Tritons. Some are due to overloading but many are due to airbags and the right bounce in the road.

orid · Senior Member

Must admit Ihad airbags on a 2006 stx Navara and towed a Jayco caravan with 280 ball weight all over Aus for over 10 years and never had a problem , didnt need those horrible leveling bars. Not that Iwould recommend air bags , just my experience has been very good . Regards Orid

Lozza56 · Member

I too have airbags, great to get the level right

I have also gone the full front rear upgrade, mainly to increase my gvm in my 200 Landcruiser 2019

You see, i and many many other were breaking the law, although the Landcruiser is big and almighty, its gvm is only 3350kg, its around 2750kg BEFORE you add weight, so put 2 adults in car, bullbar, winch, eski full of coldies and you are NOW OVERWEIGHT, and thats without adding your say 280kg ball weight from Van.

Got upgrade on van , so now i can Legally be 7,300kg combined weight, this i never get to, but its just that piece of mind

Happy travelling

Greg 1 · Guru

On a LC200 the airbags would be fine as it has a coil sprung rear end and therefore the load exerted by the airbag is on a part of the chassis designed to take it. On a leaf sprung vehicle the airbag is positioned on the axle and operates on a weak area of the chassis not designed to take a point load. There are a number of variables that lead to chassis failure with airbags on leaf sprung vehicles. 1. The amount of air pressure in the bags. 2. The load being carried in the tray and the load on the tow hitch. 3. The amount of tray overhang the particular vehicle has from the rear axle. 4. The speed that is being used. 5. The road conditions, particularly humps and heaves that impart much greater downward loads on the suspension. Depending on the above, it depends then on the number of fatigue cycles that the chassis goes through before it breaks. The greater the amount of everything above, the sooner the chassis will reach its failure point. It's a bit like aircraft wing spars. Many of these are lined due to fatigue and they are done on hours flown and often on take offs and landings which stress the spar. A short haul aircraft may need the spar changed more regularly than long haul one due to the number of cycles the spar goes through. So too with the chassis. Those with airbags on their leaf sprung vehicles, for all of the factors listed above, may not have reached the fatigue limit yet.

orid · Senior Member

Hmm I thought the bump stops on a leaf spring axle are in exact same position as coil spring axle , which indicates the chassis is designed for the extra overload at times,mind you I have been known to be wrong after 10cans, regards Orid

orid · Senior Member

Hmm I thought the bump stops on a leaf spring axle are in exact same position as coil spring axle , which indicates the chassis is designed for the extra overload at times,mind you I have been known to be wrong after 10cans, regards Orid

Radar · Guru

Gus1949 wrote:
I have a PX1 Ranger and tow a 3 ton van. On undulating roads the vehicle porpoises so I need to know which of the following is the better way of solving the problem, heavier rear springs, better shockers or air bags. I realize combinations of these will produce the best result but I am only going with one of them, caravans can be a money pit. I travel with about 100kg in the tub and a ball weight of 280kg. 99% of the time we travel on black top, not bush bashing. Looking forward to your experiences and advice.

Hi Gus

Do you have a canopy on your ute?

You say you have about 100 kgs in the tub, will that be part of the 100kgs.

orid · Senior Member

best thing here is to keep within the specified current GVM ,GCM AXLE Loadings etc., If you can't do that get a genuine gvm upgrade so that you can keep within the upgraded specified limits ,
This applies to coil or leaf spring suspension
And Yippee I think I have found someone to upgrade the GVM on my FJ Cruiser Legally so I can keep this beauty .:) :) :)
Regards Orid

yobarr · Guru

orid wrote:
best thing here is to keep within the specified current GVM ,GCM AXLE Loadings etc., If you can't do that get a genuine gvm upgrade so that you can keep within the upgraded specified limits ,
This applies to coil or leaf spring suspension
And Yippee I think I have found someone to upgrade the GVM on my FJ Cruiser Legally so I can keep this beauty .:) :) :)
Regards Orid

The biggest trouble a caravanner has with weights generally is the weight on the car's rear axle.....anything else is easily sorted.Keeping within the GCM is not difficult,in most cases,but I am amazed at the number of people who are happy to pay thousands of dollars to get a GVM upgrade to 3800kg on a popular model.These people seem not to understand that such an upgrade increases the carrying capacity of the rear axle on that car by a miserable 50kg,from 1950kg to 2000kg,and that they will NEVER be able get the front axle to its rated capacity whilst towing a PIG trailer,so they can NEVER reach that new GVM.....NEVER.Just because your car has a new GVM of 3800kg,and towing capacity of 3500kg,does not necessarily mean your GCM is 7300kg,as,in most cases,GCM stays at 6850kg.Hope this helps? Cheers

P.S And this is legal? Yeah,right!

m

-- Edited by yobarr on Wednesday 30th of September 2020 07:37:14 PM

orid · Senior Member

Incorrect Yobar , at least in my case ,I will post the specs, when I have the official paperwork .Regards Orid

yobarr · Guru

orid wrote:
Incorrect Yobar , at least in my case ,I will post the specs, when I have the official paperwork .Regards Orid

Hi Peter...you will find that what I say about that car's rear axle rating is indeed correct,and you will no doubt have noted that comments about increasing the GCM to 7300kg were qualified by the words "....not necessarily,as in most cases...",because,in some circumstances you can indeed get that increase.But it should also be noted that,with the generally accepted 10% towball weight,you will not get within coooeeer of 7300kg,with about 6800kg being top weight.Cheers

-- Edited by yobarr on Wednesday 30th of September 2020 08:50:44 PM

orid · Senior Member

Appreciate your reply Yobar very much, you have great knowledge on the matter which I do respect . Regards Orid

yobarr · Guru

orid wrote:
Appreciate your reply Yobar very much, you have great knowledge on the matter which I do respect . Regards Orid

No problem Peter,as always I am happy to help those who understand simple physics,and are willing to learn.'Happy travels' to you.Cheers

orid · Senior Member

Actually 50 kg on the xtra on the rear would do me nicely anyway , I could at least carry my spare wheel , which I leave behind at the mo ,lm on the limit at the mo with spare removed And back seats removed, and 70 litres fuel (it has an extra tank which I try not to fill) l did think of telling the missus she would have to stay behind but as Ive said before I do tend to bruise easily these days :) The upgrade is around $4000 quite expensive for the increase . But I do like this vehicle sigh!! Regards Orid

yobarr · Guru

Deleted

-- Edited by yobarr on Thursday 1st of October 2020 07:47:47 PM

yobarr · Guru

yobarr wrote:
yobarr wrote:
orid wrote:
Appreciate your reply Yobar very much, you have great knowledge on the matter which I do respect . Regards Orid
No problem Peter,as always I am happy to help those who understand simple physics,and are willing to learn.'Happy travels' to you.Cheers
Hi Peter...Today I have done a bit of research on your behalf,and I have established that the FJ Cruiser has factory axle ratings of 1280kg front and 1380kg rear. Seems there are GVM upgrades available,ranging from 250kg to 490kg,so you have plenty to consider there.However,I am yet to determine by how much each axle's carrying capacity increases with the respective GVM upgrades,but I would be astounded if the rear axle,which would be your primary concern if you are towing,did not increase by a lot more than 50kg.Top weight is 3000kg,but I suspect that your requirements are less than that? Hope that this is of some use to you?Cheers.
P.S Whilst doing research,I found this article about GVM upgrade on a particular vehicle.Interesting to see that the rear axle still is overloaded,which is what I have tried to help owners to understand.Paying big money to increase rear axle capacity by a miserable 50kg makes little sense to those with any understanding of weights.No matter how loud the cries of indignation from owners,the facts cannot be disputed by anyone with anything more than a rudimentary understanding of weights. But,be aware,the Ram 1500 is even less capable..Cheers

-- Edited by yobarr on Friday 2nd of October 2020 01:21:17 PM