Suspension setup for troopcarrier

Bart - I deleted the errored one - Ignore the Moderation email.Regards
ExplorOz Team - David
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Always working, not enough travelling ;-)

My troopy, 75 series, also is very rough over corrugations.

I remedied he problem by reducing the tyre pressure down to as low as 24 psi. You have to take it a little easy on the turns but the ride is great.

Many people have told me I risk damage to the side wall. I have just completed a 50000km, 2 year trip where I spent most of my time between Cairns and Exmouth. We were off the bitumin as often as possible and camped in spots where we didn't see or hear any thing to remind us of any other humans for up the 6 weeks straight. During this trip I blew 1 tyre on the trailer on the Gibb R Rd and and another on the trailer about 1 hour from home.

The car was heavily laden as was the trailer and with this experience I would not hesitate to reduce pressures to smooth out the ride.

Brett

G'day Bart,
can't offer any advise on the parobolic leaf springs,but if your troopy is that rough to ride in perhaps you can improve it to a satisfactory level with some cheap mods.
If I may make some suggestions,when you are on dirt roads,particularly corrigated ones,it'sassential to lower your tyre preasures by 30%.
Most people run to much preasure on the tar anyway.
as a veteran of many thousands of km of dirt, and off road driving I have learnt by experence,that the trick tought to me by Addam Plate at OOdnadatta,and later confirmed by Pirrelli,is to start with the recomended cold preasure and, after at least an hours travel,stop and recheck your preasure.
If you started with the right preasure,it should have increased by 4 psi.
More, and your start preasure was to low,less and it was to high,easy.
In my Jacko this equates to 32psi on tar 20-24 on dirt.
In the 1995" Mobil Round Australia Trial" the six troopy ambulances were running 750/16 Dunlop road grippers at 45psi front &60psi rear,they were complaining about breaking windscreens & punctures,we convinced three of them to drop their preasures to 30psi all round, they were the only ones not to break windscreens on the corrigations of the "Gunbarrel" and no more flats.
My 60 series cruiser did the 17,000km in 18 days without a single problem,in fact,useing this system I havent had a single flat since 1987,that includes" Cape york",Simpson desert" {in a 2wd isuzu kb with street tyres) and the R.A.T.
Also,if you use heavy shocks it will pull the top rubber through on corrigations,the best ,in my opinion,are the elcheepo green oil filled K.Y.B.shocks,about $30 or so each.
A susspension specialist told me to oil my leaf springs, what a difference that made.
If your not carring one tone,you can mod your one tone rear springs by taking the "set"out of the helper,(make it flat)and reset the remaining leaves to maintain the height.
It worked a treat in my 60 series,same set up as yours,try the oil thou doese'nt seem to accelerate were or any thing.

Bart,

I too can't answer your specific query re the parabolic issue, but like all of us, wanted to improve the ride a bit. I went for the option available from 4WD Systems and replaced all the bits including the steering damper. This change inlcuded the bushes - changes to nylon type, spring sets front and rear, tailored shocks front and rear plus new shackles.

The difference was amazing. The travel over rough dirt roads in the FLinders, using the same tyre pressures for LT235/80/16 of 42-44 all round, was markedly improved. I still get bounce in the rear going over spped bumps on the blacktop, but in it's element , the troopy is now very stable. The shocks were tailored for my rig, neg b/b winch and towing requirement and have performed very well.

I'm not advocating you go to them, but a coordinated, or matched replacement, of the suspension is probably the way to go.Chris
<- 1996 Troopy, the best!

I was steered away from parabolic springs by every suspension place i went too. In the end i went a little extreme and now have a reasonably rough ride, however i can endorse the tyre pressure debate.

I jbought a better pair of seats for the troopy. now THAT made a huge difference to the ride comfort.

bart,have you considered doing a coil spring conversion?there is a guy(fred's 4wd conversions)in toowoomba in qld that does it for about $1000 per axle including new koni long travel shocks.I've seen some of his work and it looks very good.
regards
jason