Outer Limits 4x4 Board

Im going to be fitting new springs soon, and was wondering if it was worth doing a Half RUF at the same time.

From all the research i've been doing, it seems almost everyone moves diff forward at the same time. I only don't want to move diff, as i dont want to mess around with steering box, driveshaft etc etc.

Im thinking if i fit rears up front, and redrill spring hanger hole 25mm back, AND redrill spring perch to bring the diff a further 25mm back, then the diff should basically be in the same location with no wheelbase increase.

I'm looking to gain a softer ride, and more flex (even if just a little more!) My current springs are very hard, and im only running 3 leafs, front and rear, and shackle angles are very poor, near vertical! Plus i get axle wrap in rear.

I have extended shackles, and when i buy new springs i will be buying OME. 4 rears.

So should i do this, or just buy front and rear OME?

Mike

no point, the whole point of the RUF is to move the diff forward to change the wb and the flex point of the car.

if youre getting axle wrap in the rear and you're not SPOA then your leaves are WAY too soft in the back...

also - extended wheelbase smooths out bumps - my front is 6" forward and rear is 1" back and its far smoother on road now (more distance between bumps, engine weight is more centralised than before).

put 2" leaves in the rear and go full RUF up front... good shocks will smooth things out, but too smooth and youll affect handling.

grimbo I can't agree with your comment, "the whole point of RUF is to move the diff forward" sure there is a definate advantage to be gained by getting that extra length in the wheel base as alien points out. But this is not the whole point of RUF, it is only one aspect of the conversion.

The main reason of RUF is to have longer springs in the front of the vehicle to improve ride and articulation. Most RUF conversions are done poorly, the diff is moved forward but shock mounts and steering box are not moved in accordance, this forces the top of the shockies backward this places unwanted side stress loads on them which makes the suspension more harsh and damages the shockies, secondly the steering arms (track rod and drag link) will bind against each other on compression of the front suspension causing the steering to lock momentarily.

To maintain correct steering geometry the steering box MUST be moved forward by the same amount as the diff this also applies to the top shock mount position.

Mike_nofx from experience if you do keep the diff in the same position by moving the mounting points on the chassis backward and forward respectively a substantial improvement in the ride and articulation is still achieved without changing the wheel base.

I know a fabricater that has been building and racing suzuki's since the early 90's, for race applications not only Class 7 but Class 8 as well he usually leaves the diff in the original position and moves the spring mounts backward and forwards, he doesn't re drill the hole in the spring mount as it leaves very little metal behind the spring, nor does he re drill spring perches because the spring was designed to work with the diff in a specific position along it's length.

My advice would be that if you do use rear springs up front keep the diff in the same position and move the spring hangers by cuting them off and rewelding them in the correct position tosuit the longer spring. This has proven to be reliable for off road race conditions.

If you want to achieve and take advantage of a longer wheel base as well then you really should move your steering box forward, lengthen or spacer the rod from steering column to steering box, lengthen or spacer front tail shaft and move your shockie mounts. Unfortunately the steering box can't be moved far before you have to cut the tubed front chassis cross member. In QLD this will draw the ire of the transport inspectors and you will be lucky to have the conversion approved.

x2 504_matt.

However, with bumpstop spacing to prevent interference between the tie rod and drag link, I've found no problems with full RUF and the steering box in the standard position.

RUF is a lot of work to do properly.

Steve.

Yeah Steve I forgot to menion that, a lot of people do space the bump stops down to prevent the diff from going up far enough for the steering arms to bind. This will stop the steering arm binding problem but in doing so you limit your upward wheel travel. A lot of people don't see this as a problem because they run huge tyres and limiting upward wheel travel stops the tyres from travelling up and fouling on the guards. Front diff housings however can get bent from smashing into the bump stop instead of moving through a full range of motion. I like the idea of lots of wheel travel to keep those tyres in contact with the ground

It really depends on what you hope to achieve from your RUF conversion, you can achieve better ride with better articulation, wheel travel, flex etc .... but as Steve said "RUF is a lot of work to do properly"

by moving the diff forward you are shifting the diff sightly in front of the centre point of the engine, this dramatically improves the flex and the balance of the vehicle.

Im thinking if i fit rears up front, and redrill spring hanger hole 25mm back, AND redrill spring perch to bring the diff a further 25mm back, then the diff should basically be in the same location with no wheelbase increase.

This is exactly what I did when I did when my RUF. I got a heap more flex and a lot softer ride. The diff did still go forward slightly tho. I'm thinking off extending the wheel base a little bit so I can shorten the shackles because they hang out to far and get caught up.

I appreciate that a wheelbase increase will definately be beneficial. If it were a simple job (which for the more experienced it probably is) i would do it, but I dont really want to be re-welding spring hangers, extending the chassis, moving and modifying my steering.
I don't have the cash to pay someone to do it, and while i can weld, i dont feel confident to be welding and modifying such critical components.

I'm going to be replacing my current springs regardless of the RUF or not, I'm not happy with the ones fitted. Just trying to decide wether i buy 2 fronts and 2 rears. or 4 rears. So far i'm still leaning towards 4 rears.

I know some people here think that by NOT increasing wb, then the procedure is pointless, but it wont cost a cent more to buy 4 rear springs (over 2 F and 2 R) and if gains are to be had, even 5mm more flex, and 2% softer ride then i'm all for it.

I will be buying OME (+40mm), because from what ive heard they are the best. And apparently one of the only manufacturers who actually make their raised springs longer, instead of just adding arc to standard length springs. This is one of the problems with my springs now, plenty of arc, but my shackles sit near vertical, the other problem is that they are rock hard!

alien wrote:if youre getting axle wrap in the rear and you're not SPOA then your leaves are WAY too soft in the back...

Because the springs are so stiff, im running only 3 leaves in rear. And because the springs dont have any flex, both clamps are removed. EDIT: Actually only the rear clamp is removed.

I only notice that it wraps if i take off too quickly, it makes a slight knocking noise which i believe is the drive-shaft uni-joint binding.

Mike

And apparently one of the only manufacturers who actually make their raised springs longer, instead of just adding arc to standard length springs

If you used these springs it won't move the axle as far forward because as you say they aren't any longer than stock whereas new OME's are. It could save you a fair bit of money just buying new springs for the rear and using the current ones up front. And with the current springs being so hard it could be beneficial for the front end anyways in a RUF because I had to add a spring to my packs to make it stiffer so it would handle better and not ride on the bumpstops as often.
The steering shouldn't bind if you do the RUF the way you described as mine didn't and a few others on here have done the same with no troubles.
If it was me I'd just buy new rears and use the ones you've got up the front because it won't cost you anything if it works out and a new set OME rears are only as far away as your closest ARB if it doesn't work out.

Firewall clearance? I'm on 15x7s so my scrub radius isn't that big and at my height, without the axle coming forward it would have been a difficult fit.

I'm running a half RUF with the perches redrilled to push the axle further forward, probably close to where it would sit with a true RUF. SPUA, no bodylift, bumpstops and standard steering box. Working the headlight bucket was easier than the firewall. I'm about to go power steer and hope to create some more space so that the axle can come further forward still.

So while I agree with some of Matt's comments (well written and well thought out Suzuki forum), axle location and it's associated effects is the biggest benefit.

mike_nofx wrote:I will be buying OME (+40mm), because from what ive heard they are the best. And apparently one of the only manufacturers who actually make their raised springs longer, instead of just adding arc to standard length springs.

I am sure that is a myth that OME loves to hear lol, there are plenty of manufacturers who add length aswell as arc, but there are some dodgey ones who don't.

Kitika wrote:If it was me I'd just buy new rears and use the ones you've got up the front because it won't cost you anything if it works out and a new set OME rears are only as far away as your closest ARB if it doesn't work out.

Good idea, and this is what i will most likely end up doing.

Firewall clearance has caused no dramas so far. Seams are flattened, and there has been previous guard massaging.
I also have 2" body lift, 2" bump stop extensions, extended brake lines, and quite narrow tyres, 33x10.5" (31.85" actual dia).

I have the hilux/commodore shocks, could these prove to be a problem?

As for the OME springs and 'myths' i have just heard so many good stories about them, so many happy customers, and not a single complaint. Hard to argue with that, so they are my choice.

By the way, does anyone have the eye to eye length measurement of a rear OME spring while fitted to the car?
My current springs measure at 989mm

Thanks for all the useful info guys!

Mike

GRPABT1 wrote:

mike_nofx wrote:I will be buying OME (+40mm), because from what ive heard they are the best. And apparently one of the only manufacturers who actually make their raised springs longer, instead of just adding arc to standard length springs.

I am sure that is a myth that OME loves to hear lol, there are plenty of manufacturers who add length aswell as arc, but there are some dodgey ones who don't.

lovells do good 2" leaves that arent too stiff and are longer than stock (correct shackle angle).

all your doing by not moving the diff foward is shittening your approach. A lifted zuk's with big tyres front wheels are ridiculously close to the firewall imo. (even including the fact that the diff moves foward on compression)
Even a small amount foward is better than nothing. Keep it under 20mm and (from my experience with extended bumpstops, which with a decent sized tire & low ride height you should ahve anyway...) you should have no issues with drag link/tie rod scrub or shocks fouling shock towers.

I wouldn't look at ome fronts any more (if modifying for primarily offroad benfits), i'd go rears and leave it stock WB by redrill etc just to get more owntravel & better ride thats offered in a well setup longer spring. even at the detrement to approach angle (which is bad enough as it is with a leaf sprung car). 20mm extension is negligable in some ways, it cant hurt to move it foward if there's no fouling & your installing longer springs anyway. With a 7" larger tyre on my car, + the increase ride height with suspension & body lift I seriously want an 88-90" plus wheelbase over the 82"ish (negligable increase, more to centre fat tyres in guards than to improve ride etc), its just the bodywork is so paper thin & too much work for me to look at to try & achieve a decent extension.

Please don't get me wrong, I am not debating the benifits of moving the diff forward in fact my own Suzuki is a full RUF, but I have correctly positioned my shockies with the use of shock hoops, my steering box has been moved forward and for further balance I have moved my engine back. I am simply saying that if it is going to be done it needs to be done right. If you do not move your shock mounts and steering box everything after that is a compromise to negate the problems you have just created by not moving them.

Dee, you make the coment about poor aproach angle due to leaf springs, what modern 4x4 has better aproach ange than a Suzuki Sierra?

Fitted up the new OME rear springs to the rear today.
Not as good of a fix as i had hoped! (No fault of the springs tho)
It hasn't improved shackle angle. The shackles i am using are extended (from memory about 125mm eye to eye???) Will shorter shackles make much/any difference? They are not dead vertical, maybe about 10-15deg off vertical as a guess.

On the plus side, springs are nice and soft, I removed the very bottom leaf. Without shocks fitted the springs are nice and (very) soft. Once i connected up the shocks (gabriel hilux/commodore) it stiffened it up heeeaps! Will need to look into new shocks soon, they are too stiff.

Also, it has leveled out the 'Sierra Lean' a lot, only sits about 15-20mm lower on right side now (could be due to the front leaning still) previously i had a lean of about 35+mm.

Will start on the front end over the holidays.

Thanks for all the help guys

Mike

The lean won't be fixed, you'll be back to where it was soon as the springs bed in to some degree.

Like I said the OME leave's are not uber long like some people say. Maybe you should have gone hilux fronts on the rear with those shackles. Otherwise just get shorter shackles. Good shackle angle is waaaaaaay more benifitial than shackle length in my experience.

Did the job today. I ended up moving the diff forward (Or didn't, depends how you look at it!) I used the original spring locating holes in the perches. So the diff is sitting roughly 1" forward.

I did re-drill the rear spring hangers 25mm back though. I didn't want to, but the shackle angle was too big. This has made it more acceptable.

I measured my driveshaft before and after. Before i got 695mm flange face to flange face. Now i have 715mm. So its 20mm longer. Should i look at getting a 20mm spacer, or is it ok as is.

Im running 3 leafs on left side, and 5 on driver side to correct lean, and compensate for my extra weight (90% or the time im the only person in it) originally tried only 4 on the driver side, but it still sat lower! So with the full pack of 5 it sits higher now, which i think is good.

The measurements of wheel centre to flare before were: Left-600mm Right - 550mm. (50mm lower on driver side) Now with the RUF and 5 leafs on driver side its: Left-550mm Right-585mm. (30mm higher on driver side) Once my 105kgs get it, it should level up a bit better.

Mike

5 on one side and 3 on the other! that would suck, your flex is going to be much more restricted with 2 extra leaves on that side. I woudl run 4 and try and shift some weight to the passenger side like spare wheel, battery etc.

GRPABT1 wrote:Otherwise just get shorter shackles. Good shackle angle is waaaaaaay more benifitial than shackle length in my experience.

Shackle length is far more important then the angle of it. Just making do with where the mounts already are and making a shackle some length to make the angle look good doesn't take into consideration the length and arc of the spring. The angle should merely be a side effect of having the correct length shackle/spring/mount combination and set up.

GRPABT1 wrote:5 on one side and 3 on the other! that would suck, your flex is going to be much more restricted with 2 extra leaves on that side. I woudl run 4 and try and shift some weight to the passenger side like spare wheel, battery etc.

When i tried 4 the first time, it still sat much lower than the left side. Once i added the 5th leaf, the short stubby one, it brought it up a fair bit.

If i try 4 again, should i keep the short bottom leaf in, and remove the 2nd leaf from bottom?

Mike

I thought OME leaves had extra arc on one side to counter the sierra lean? Are you sure you don't have them arse about?

GRPABT1 wrote:I thought OME leaves had extra arc on one side to counter the sierra lean? Are you sure you don't have them arse about?

not the dakars. sounds more serious than a spring arch problem. have a sierra in my shed at the moment that has 2 extra leaves on one side......just a little bit bent chassis.

joeblow wrote:

GRPABT1 wrote:I thought OME leaves had extra arc on one side to counter the sierra lean? Are you sure you don't have them arse about?

not the dakars. sounds more serious than a spring arch problem. have a sierra in my shed at the moment that has 2 extra leaves on one side......just a little bit bent chassis.

Im running the new OMEs on the rear, and my old rears (brand unknown) on the front. So the old rears are probably not in the best condition anyway.
When i got the OME's they weren't marked right and left, i just put them on a flat surface, and the one that looked higher went on the right side, was only about 2-3mm higher tho. all the number codes on the leaves were the same. I also removed the very bottom leaf on both.

With regards to the front springs (the old rears) If i go back to running only 1 leaf extra on the right side, which leaf has the most effect in height increase, the short bottom leaf, or the one 2nd from bottom (long leaf)

Mike

so are the dakars better or worse then the ome springs?

Mine have OME painted on them...