Leaf Spring Tech

[beebee]

I've heard it said a number of times that "the flex in a leaf spring comes from the front half of the spring". This is why people persist in intalling longer springs I assume. But in the case of a hilux, the centre pin is not in the center, it is toward the front of the spring by a couple of inches. As such, according to me, if you turn the spring around so that the longer section is at the front, you will achieve more flex. True? If the desire is to maintain the standard wheelbase, then why not just reposition hangers?

I got hold of some hilux IFS rear springs today for $45 ea in good condition. They are 1300mm long as opposed to the 1200mm standard. If I receive positive feedback about this "turning around" idea, then this is the way in which I shall mount these

[beebee]

Would also have benifits for departure angle with less length at the rear of the axle.

[bobtail]

LEAF springs there only good for box trailer,s

[dave]

one thin have you considered that the spring is taller in the rear half than the front to match the chassie rail hieght change

[beebee]

Dave, I hadn't thought about that but it shouldn't be a problem. When I onstall the new suspension setup (what ever it is) I will be rotating the spring perches on my housing anyway to raise the pinion angle. I will also be trussing the housing, installing armour as well as an anti-wrap bar so a bit more welding won't hurt. Thanks for the imput though.

[cuz]

If you know someone who does machine shop work,maybe they could make you some thing like these.
What they do is offset the axle on the spring,either foward or back depending on which way you put the offset,also if you got then angle milled you could use them to fix your pinion angle.

[drunkenperformance]

ARB has plates for landcrusiers to change diff angle off the shelf...you just have to is shave the sides cos crusiers have a wider leaf pack...i think they are avaliable up to 2deg and cost under $20, works out cheaper than getting somebody to throw it on the milling deck

Cheers Dan

[beebee]

Drunkenperformance,
I've thought about using those types of plates and will probably do so on the front diff. I didn't know that they were that easily available though.

Cuz, if I were to turn the springs around, I doubt that those plates would be able to relocate the diff far enoung to suit the spring. The centre pin is off center by quite a few inches. I could always just drill and reposition the centre pin but I'd prefer to move the chassis hangers.

[hypo]

beebee,

if u turn the springs round as u say that will move the diff backwards right ?? is this such a bad thing ?? i mean u dont have 2 bob it as much, u will decrease ya departure angle and if there is more of the spring in front of the centre pin it will greatly reduce axle wrap nence u may not need a track bar ..

just a few thoughts and opinions dude

[beebee]

I don't pretend to know what the "perfect" wheelbase is but at the moment I'm pretty happy with it and don't think I want it any shorter. Also if I change it I will have to alter driveshaft and brakes. Although it isn't much (well not enough to make me rule it out totally) its more, as I see it, unnecessary stuffing around. Although a longer tray would be cool. Altering the wheelbase would also rule me out of modified class in XRCC and put me into Open if I understand the rules correctly. And the coment about axle wrap is warrented as I had though of this myself but was unsure of whether it was the front or back that kinked due to this phenonenon (?).

But more importantly, would the setup that I propose give benefits in the flex dept?

[ShortyMQ]

beebee,
if you are going to move the front mounts you should look for a spring that has the same distance(or close to) from each end to the centre bolt, this will give better flex than a spring with one end shorter than the other.I think one model of the ford courier has a spring that suits as it is the same width as hilux,is longer and has a more centered centre bolt and if you move the front mounts it won't alter your wheelbase,but won't improve your depature angle either.Hope this helps

[beebee]

I'd like to be able to say "No officer, they're standard hilux springs."

But I can see what you're getting at. I would like to use the springs that I've already got though.

Does the concept of having the longer section of spring at the front thus giving more flex hold water? Or are there too many holes in my theory? Hopefully I'll be doing a few Mechanical Engineering subjects next year so I should be able to answer these types of questions for myself.

[Hybrid]

Mechnaical Engineering. Nice one, I was wondering what to do for my electives next year.

John

[beebee]

John,
Here I was thinking that I had another informative reply to my thread and it's just you trying to get your post count up!

But do you reckon it'd work?

[hypo]

y worry if they r lux spring or not just get it engineered and then wen the orificer tries 2 book ya say oh and by the mate here is my engineers report so shove it just like i did yesty

[Hybrid]

John,
Here I was thinking that I had another informative reply to my thread and it's just you trying to get your post count up!

But do you reckon it'd work?

Posts are counted? Anyway, I had been thinking along the same lines since I heard that the flex comes from the front of the spring and the pin is mounted forward of centre. This is just from comments made on here though. I haven't seen any technical answers as to why this is. Every time someone talked of redrilling and moving their pin I wondered if you could just turn the spring around. Put it this way. Will it cost you much to do? I doubt it. You may aswell try it cause at the least you'll get a better departure angle. Plus this way your Lux continues to be my test vehicle.

So does this mean if your shackel were at the front of the spring the flex would come from the back of the spring?

[beebee]

Engineered.....? That'll cost too much and I can't see myself getting through. What with a welded flipped double arm crossover steering setup and all. What do you do when you make a change though? I suppose it would be worth waiting until most of the work is finished before bothering with the engineer. I don't even know where to find an engineer though and especially a 4wd friendly one. How much did it cost you hypo?

Hybrid, don't ask stupid questions - especially one's that you know I can't answer. Is it like that tree falling in the forest sort of shiat?

[hypo]

i think from memory it cost me bout 350 and yeah i dunno wot happens if u make a change i guess u go back and he charges u a lesser amount and just has 2 look at tha latest mod. i dunno man

[beebee]

How many mods did he look at for your $350?

[hypo]

heaps.

dropped front hangers, body lift, hysteer(arms, tierods,p/sbox mounting), shock hoops, extractors and exhaust, custom tray and mountin point, 35's, trac bar, extended shackles(front bought and rear custom both 4" over standard), new rear spring mounts, rear ubolt flip, rear shocks( / \ ), bobbed chassis. um i think thats bout it

[beebee]

Did you talk to him before you did the mods? Did he knock anything back? Sounds like good value to have everything legal.

[Hybrid]

Hybrid, don't ask stupid questions - especially one's that you know I can't answer. Is it like that tree falling in the forest sort of shiat?

I wasn't asking you, farkwad, I was making the safe assumption that there were more cerebrally gifted people on here than you. I'll say your name when I'm directing a question to you.

(comment directed to Beebee) Surely if Hypo can get all that stuff engineered, including different springs and moved spring mounts, getting reversed stock hilux springs and moved spring mounts engineered can't be that hard. (end of comment directed to Beebee)

[hypo]

didnt talk 2 him b4 and i just made sure i did everythin right the first time (with the help of A1ZOOK!!)