Outer Limits 4x4 Board

The suspension setup on the back of a 4wd will effect how the front travels and the the front will effect the how the rear travels...Is this correct?

The reason I ask is I have taken off my blinders and I am looking at every possible option in regards to getting extra travel. I ramped it this afternoon and the results were interesting.



When I put the front wheel up the ramp, it honestly looked like the front was being limited by the shocks...as the shock was at full extension and the shackle was not inline with the leafpack. The below pic is the front end at full travel.



So I removed both front shocks and tried again...the results were no different...It was then I noticed the back.

at the back the shackles were fully inline with the leaf pack and therefor not allowing any more travel. See pic below.



Basically what I am asking is if I was to put extended shackles on the rear and have them at the correct angle I would gain extra travel...but would this extra travel allow the front to travel more???

Here are a few measurements I took if anyone is interested....

FRONT UP RAMP...(Measurements taken from centre of hub to bottom of gaurd...2 inch spring lift, 2 inch body lift)

Down Travel = 770mm
Up Travel = 430mm

The rear is a bit difficult to compare with other trucks so I wont put that info up...but if someone could please put up the measurements of their trucks up (centre hub to bottom of gaurd) that would be greatly appreciated!

In playing around with your 60's setup, in order to get more travel out of the front, you will need to weigh down the tray a little more.

When i uted my 60 (mucking around for a brief time) i noticed the front end travel dropped significantly, and i was picking up the rear wheels really easily.

I feel if you were to put extended shackles in the rear, you will find it will become more unstable rather than help your front to work.

On the other hand, if you give the rear less travel, you are more likely to start picking rear wheels up.

Try chucking a few bags of concrete on the rear of the tray and see how it performs. And you will need to change the front shocks if you want more travel also.....but for testing sake, just disconnect them like you did before.

I am going to move things around when I get the chance to better distribute the weight...the two batteries will end up behind the cab (under tray). Also going to move the compressor (not much weight I know, but it all helps) to the tray area as well.

Trying to think of other ways I can shed weight from the front end...a little here and a little there...might make a difference!

shifting as much as you can will help

but before you do it , get it weighed ;
front weight
rear weight

also keep in mind what a standard 60 weighs and compare your 60 ute overall weight
the springs themselves may need leaves removed or even custom springs

if you had the money a spring over would greatly improve the articulation...

but that is sort of taking it to the extreme... what about superior drop shackles??? arent they supposed to help with flex???

cheers

The setup that I did to my 40 when I owned it was to put in extended shackles, extended main leaf and remove some leaves from the pack. This worked extreamly well. Bob at allset did it but It would not be hard to do yourself though. Removing the leaves will allow it to flex more now that you have not got the weight on it. Less leaves less resistance.

The longer and flatter your springs are the better they will flex. I would try taking bottom leaves out and extend the main and wrap and add longer shackles. This would be a cheap option to try. Always try before you go and buy new shocks as you may have to get longer again.
Also clamp the front of the rear spring but take the back clamp off. This will let the leaves open on the back.
If you go too soft in the rear, you may need a ladder bar to stop axle wrap.

I may be wrong but here's my take on it. Firstly my truck flexes great in the front but sucks in the rear - why? i think its from a combination of several reasons. firstly in the rear i have a LOT of weight but the springs need to be quite strong to support it. as a result the rears refuse to compress to the stops. The fronts do compress to the stops.

So the first point i make is that in order for one side to droop it has to be forced down by the leverage action of the other side compressing to the stops.

Secondly, if you only have extended shackles i think you will make the best use of them by having longer main and wrap springs. By doing this you will either have A. same lift/closer to horizontal shackles with flatter spring arch and therefore more length available for droop or B. Higher lift by arching/setting springs and maintaining acceptable shackle angle which gives more available compression.

my two cents. tell me if you agree or disagree. I Think it all makes better sense if you approach it from a geometry point of view. I think spring rate is also important, but more on an individual axle point of view. I don't think that the relationship between front and rear axles is as important as making sure the springs at each end are matched to the weight that they carry individually

dybes wrote:if you had the money a spring over would greatly improve the articulation...

cheers

A spring over will give you alot more height but it wont give you any more flex

jimbo

jimbo jones wrote:

dybes wrote:if you had the money a spring over would greatly improve the articulation...

cheers

A spring over will give you alot more height but it wont give you any more flex

jimbo

True indeed. The advantage of the spring over is that you can run a long soft flat leave pack to get the flex, and still have a descent ride hight to fit 35's and above. A spring over with standard leaves and shocks will have pretty much the same potential travel as a standard setup.

Layto....

lay80n wrote:

jimbo jones wrote:

dybes wrote:if you had the money a spring over would greatly improve the articulation...

cheers

A spring over will give you alot more height but it wont give you any more flex

jimbo

True indeed. The advantage of the spring over is that you can run a long soft flat leave pack to get the flex, and still have a descent ride hight to fit 35's and above. A spring over with standard leaves and shocks will have pretty much the same potential travel as a standard setup.

Layto....

I dont nessicarily agree with this, in SPOA config you get more leverage against the spring. In a static droop setup, they will both go about as far (all four wheels off the ground) but as you now have another 100 or so mm worth of compression travel you can do two things
1> Force the wheel further into the guard (if it will fit) this wil casue the second thing
2> force the spring/wheel on the oposite end of the axle to be "rotated\twisted" more forcing the wheel further down.

lighten your springs and get the two main leafs on each pack lengthened.

love_mud wrote:

lay80n wrote:

jimbo jones wrote:

dybes wrote:if you had the money a spring over would greatly improve the articulation...

cheers

A spring over will give you alot more height but it wont give you any more flex

jimbo

True indeed. The advantage of the spring over is that you can run a long soft flat leave pack to get the flex, and still have a descent ride hight to fit 35's and above. A spring over with standard leaves and shocks will have pretty much the same potential travel as a standard setup.

Layto....

I dont nessicarily agree with this, in SPOA config you get more leverage against the spring. In a static droop setup, they will both go about as far (all four wheels off the ground) but as you now have another 100 or so mm worth of compression travel you can do two things
1> Force the wheel further into the guard (if it will fit) this wil casue the second thing
2> force the spring/wheel on the oposite end of the axle to be "rotated\twisted" more forcing the wheel further down.

Thats going to depend on the shocks he is running though. As i said in my post, a spoa with standard will be limited still. I understand what you mean about the forced articulation bit (my rig works like that ). To get significantly longer shocks in there he will probably then need to modify the mounts.

Layto....

The best way to think of your 60 with no weight on the rear tray is to liken it to a single axle trailer, with the goose neck being your rear spring setup and the single axle being your front setup.

The bulk of the weight is over the front axle and because there are no balancing forces trying to use the rear axle to take some of the load, the front is not doing a lot of work. The rear (goose neck) is doing all the work to keep the wheels on the ground. Single axle trailers don't articulate their suspension.

If you dont want the weight to make it work better, you can harden the rear springs, or soften the front springs. As you are well aware though, softening the front springs will loose you ground clearance, but make it flex better, and hardening your rear springs is more than likely going to help you pick up rear wheels and ruin ride comfort.

To get the best of both ends, you need to try and distribute the weight more evenly over both axles and match your springs to the load carrying characteristics.

Make sense?

ToyTruck wrote:shifting as much as you can will help

but before you do it , get it weighed ;
front weight
rear weight

also keep in mind what a standard 60 weighs and compare your 60 ute overall weight
the springs themselves may need leaves removed or even custom springs

i put my middy on the fork at work the total is 2190kg
when i did the front i thought 1300kg for sure cos it has pto and a big 4' heavy tube bar but it was 1100kg i was very surprised

Thanks for all the replies guys...it makes for some interesting reading on what some of my options are.

I am having trouble finding somewhere to weight the truck so I can get front and rear weights....not just entire vehicle....any ideas there?

if you want to find some cheap longer main springs for your rear spring packs you mind be able to find some 75/78/79 rear spring packs from a wrecker cheap.. its pretty easy to pull apart the leaf packs and fiddle with the leaves..

think i paid about $75 for a pair of springs from the wreckers a while back..

G_loomis wrote: I am having trouble finding somewhere to weight the truck so I can get front and rear weights....not just entire vehicle....any ideas there?

Find someone that builds race cars and if they cant do it they'll know someone that has the individual scales to weigh the car front to back, left to right and seperate weights of all four corners...

http://www.americanweigh.com/index.php?cPath=64