Outer Limits 4x4 Board

I stumbled across a thread the other day (that I cannot find now) that said by removing one bolt from somewhere on the front suspension, it would act similarly to an xlink. Does anyone know what this one bolt is and what it's dis/advantages are?

I think it was one of the four big ones underneath the axle on whatever those arms are called.

The bolt your referring to would be one of the 4 in the Radius arms, and yes it will help flex marginally due to the removal of the restriction posed by those bushes.

But. this should NEVER EVER be done whilst driving the vehicle.

If that remaining bolt shears the diff will go where it wants to causing major damage and or worse.

Not to mention the extra force on the remaining bolt may warp or twist the mounting points

I've seen a few guys do it (off road low range only) it does work.

But I've never been that hard up for flex to be bothered doing it.

Black Bull wrote:The bolt your referring to would be one of the 4 in the Radius arms, and yes it will help flex marginally due to the removal of the restriction posed by those bushes.

But. this should NEVER EVER be done whilst driving the vehicle.

If that remaining bolt shears the diff will go where it wants to causing major damage and or worse.

Not to mention the extra force on the remaining bolt may warp or twist the mounting points

What he said. If the other snaps your in severe faeces

Black Bull wrote:
But. this should NEVER EVER be done whilst driving the vehicle.

I couldn't agree more.

Stop the vehicle first

http://www.youtube.com/watch?v=MGcrF3aL8uk&NR=1

I'm not necessarily condoning this mod for 100 series owners, but there's two effects from pulling a radius arm bolt.

Assuming spring and shock lengths are adequate , you will achieve every bit of flex possible in you suspension. That's not normally the case with radius arm suspension, especially when climbing.

The reason is that radius arm suspension has very high roll stiffness, especially compared with the 5 link rear in 100 series. By pulling one bolt, basically, all of the roll stiffness the radius arms are introducing is removed.

This will normally result in inadequate roll stiffness on road- making for "odd" handling and the car will be squirelly- it will feel like it's rolling around the front end.

This is why it might not be a good idea.

However, I'm not 100% buying the "increased stress" argument. Yes, remaining bolt is under more load but that's not the same as stress - a radius arm suspension puts enormous stress on these bolts as the weight of the car and the length of the radius arm is trying to tear to bolts apart. Once you remove a bolt, the bolts don't experience these stresses any more - only consistent load from the weight of the vehicle.

Yes, I know this is a simplification, but in a hard working suspension off road, I reckon there's a case lower stress is better than higher load.

PS I actually think the front of 80/100 series cruisers flexes fine with no swaybar but all the bolts in. I'm planning to radius arm the front of my suzuki and designing it to run with a bolt pulled, as I prefer low front/high rear roll stiffness suspension, and I'm using arms from a heavier car (range rover) so I'm already starting with excessive bushing stiffness.

Steve.

No-one has mentioned the lop-sided braking response from a hinged radius arm.

You end up with all the braking reaction being taken through one arm and all the anti-dive acting on one side of the vehicle. Not good for traction or handling. Especially if you're not expecting it.

Ok, so it might/might not be a bit dangerous, if I was to do it to have a little look see at the difference, which bolt in particular should it be? like front left or ??

KiwiBacon wrote:No-one has mentioned the lop-sided braking response from a hinged radius arm.

You end up with all the braking reaction being taken through one arm and all the anti-dive acting on one side of the vehicle. Not good for traction or handling. Especially if you're not expecting it.

Pauline Hanson??? (Please explain)

crunk81us wrote:Ok, so it might/might not be a bit dangerous, if I was to do it to have a little look see at the difference, which bolt in particular should it be? like front left or ??

so even after being told of all the dangers and shit, you still wanna do it just to have a "little look"....?
I recommend undoing the nut behind the wheel..

The point about dive under braking is a good one. If I extrapolated how bad my car is under power with one rear bolt removed to the front it would be deadly under brakes on road where far more torque can be applied than under power.

Steve.

Any extra leverage across the length of the axle will put side load on the other bolt. These bolts are good for tesile and shear but will snap when given a side twist load.

Bazzle

fester2au wrote:

KiwiBacon wrote:No-one has mentioned the lop-sided braking response from a hinged radius arm.

You end up with all the braking reaction being taken through one arm and all the anti-dive acting on one side of the vehicle. Not good for traction or handling. Especially if you're not expecting it.

Pauline Hanson??? (Please explain)

On a radius arm front suspension, all the torque your brakes apply to your front wheels is resisted by the radius arms lifting up on the chassis at their mounts.
If you take one bolt out, then you're relying on one radius arm to take all the brake torque and it puts all that brake torque into one side of the vehicle.
This will make the vehicle dive to one side under hard braking.

To compound the problem further, you have different downforce and hence different traction on each front wheel.

crunk81us wrote:Ok, so it might/might not be a bit dangerous, if I was to do it to have a little look see at the difference, which bolt in particular should it be? like front left or ??

champ its all fun and games until you snap the pinion flange off, tear your brake lines apart and whatever else.
Definitely dont do it while driving. if you want more flex by undoing 1 bolt you will probably get more flex then normal by undoing 1 end of your shocks?
but again dont drive it (onroad).

or accept it for what it is and know the front flexes poorly.

bogged wrote:

crunk81us wrote:Ok, so it might/might not be a bit dangerous, if I was to do it to have a little look see at the difference, which bolt in particular should it be? like front left or ??

so even after being told of all the dangers and shit, you still wanna do it just to have a "little look"....?
I recommend undoing the nut behind the wheel..

I dont think he's going to be tearing around at 80 kph.... If he wants to try it its up to him!!! he knows the consequences that may occur. Deal with it.

Left hand front bolt I believe (not 100%)

"bogged"so even after being told of all the dangers and shit, you still wanna do it just to have a "little look"....?
I recommend undoing the nut behind the wheel..

I think this statement is right on the money regarding alot of the questions asked here and other forums.

-Scott- wrote:I've decided that half the people who come to a forum asking questions merely want just one other person to tell them the answer they want.

It doesn't matter what other opinions are offered, or how well the answers are backed up by theory, or experience, or just plain old common sense - all it takes is for one person to post the answer they want, and that's what they'll do.

You can lead a horse to water, but you can't make it drink.

KiwiBacon wrote:

fester2au wrote:

KiwiBacon wrote:No-one has mentioned the lop-sided braking response from a hinged radius arm.

You end up with all the braking reaction being taken through one arm and all the anti-dive acting on one side of the vehicle. Not good for traction or handling. Especially if you're not expecting it.

Pauline Hanson??? (Please explain)

On a radius arm front suspension, all the torque your brakes apply to your front wheels is resisted by the radius arms lifting up on the chassis at their mounts.
If you take one bolt out, then you're relying on one radius arm to take all the brake torque and it puts all that brake torque into one side of the vehicle.
This will make the vehicle dive to one side under hard braking.

To compound the problem further, you have different downforce and hence different traction on each front wheel.

Ah the light comes on now. I thought the talk was about removing a bolt from both sides eg both front bolts to mimic a bit like an xlink but I see now the theory is to remove one bolt from one side. I couldn't work out how removing both sides would load up just one side

just go out and buy a front locker, what flex you have will be enough , or you can fit a XLINK dont play around pullin bolts even off road , cant imagine how much fun it would be puttin said bolt back in all goo and mud stuffed in there let alone gettin it to line up,,, ohh what a feelin

I haven't done it with a Landcruiser, but have tried it with a Land Rover.

The best bolt to remove is the front bolt from the left hand radius arm.

Then you only have the right hand radius arm to prevent the axle assembly from rotating under the vehicle.

The forces that try to make the axle rotate under are created by braking, tractive effort, or hitting obstructions. Off road the worst of these would be hitting an obstruction (particularly with the left wheel) - but the driver has some control over that and a spotter could watch what is going on. Since speeds off road are generally low the risks are not particularly great.

So if you want to try it off road go ahead and work it up carefully until you are confident under the various situations you might encounter. Articulation and body roll will increase.

However if front articulation is not too bad now, it hardly is worth it.

But you should not drive on the road with the bolt out. The unequal forces in the radius arms under hard braking will adversely affect the handling and steering - the last thing you want is for your vehicle to change lanes at speed if you have to brake hard in an emergency.

You might get more articulation, but will your shock lengths allow it?

And if they do, are they bottoming, or have you raised bump stops?

Paul

I have owned Patrols for 10 or so years and have never done it.
A guy that I have wheeled with for probably 5 years does it nearly every trip. Shorty patrol, locked, geared, 37s. Always puts it back in before he gets back on the bitumin.
Never has a problem.

ive found in my 60 series (runing 80's coil setup) it make a big differnece when flexing removing one rear bolt from the front arms, the front wheel drops ova 4'' more and the other wheel pushs up mor also. with all bolts in it puss for flex, drive about the same so far, but i would only ever do this when offroad,

as stated could/will put more load on the remaining bolt left in. im not so sure about that, not when flexing as far as i can see, maybe when normal driving? i guess i find out if it brakes one day off road?

dan.

put it this way, a 80/100 series or a GQ/GU patrol weighs what? bout 3 tonnes ?

Now when you hit the brakes the diff wants to rotate, those 4 bolts stop it from doing so.

Now, multiply 3 tonnes x speed x tyre size and the distance from the theoretical pivot point. and also add in the shock loading if you hit something plus of course the torque from the driveline

That remaining bolt may have as much as 6-10 tonnes of force applied to it. Still want to do it ?



I cut my tyres till the belting is exposed...gives me more traction

Its up to him. My mate does it, but only when he is in low range situations. Defiantly no high speed stuff. Yes u do wanna be carefull. It feels like the front diff is walking around and plenty of body roll. But if your only crawling you will be okay.


Why not look into superflex arms from superior. Easiest way for front end flex.

By a "little look I was thinking of some simple low speed testing at my Dad's property. He's got a beautiful washout there for looking at wheel travel, all low range 1st gear stuff.

Thought it would be interesting to test, and maybe use to get past an obstacle if needed. You know the one where you think ' if I had just a bit more front travel i could get through that.

I would never drive it on the road with a bolt missing! :o

Will be giving it a "little look" soon

I do it all the time, mates as well, have done for 12 months and never had a problem and works a treat. Don't knock it til you have tried it. As for the stesses going all through one bolt, yes technically they are, but what X LINK doesn't? Yeah, all the bolts are in, but that ONE BOLT, the pivot in the middle, performs that same anti rotational properties that the 2 front factory bolts fixed to the diff did. Not to mention the weld quality and structural stresses placed on the housing where previously there were none. The rear of each radius arm is also mounted via ONE BOLT. A frames also are pivoted off ONE BOLT. Not saying there aren't some awesome welders out there, I've seen some fabrication that would put the factory components to shame.

But, true to what the other guys have said, on road, it handles like sh1t and does want to pick up the driver's side of the car under braking, so I put it back in before going home. Besides that, your insurance would be wiped as well if you had an acco.

IMHO it can't hurt to LOOK, the only thing to be careful of is when the passenger side, (the side you take out the bolt), is under compression, be sure the front end of the arm doesn't rotate up into the diff housing. It comes close on mine but then again I have castor plates for the lift so there's an extra inch or so clearance.

beast of a GQ wrote:
Why not look into superflex arms from superior. Easiest way for front end flex.

has any one seen them work? i cant really work out how there bolt up? do they bolt to both the origanal radius arm bolt holes or just one? if it was just one would in not just put as much spress on the one bolt as removing a bolt from a stock setup then!!!

hurricane wrote:

beast of a GQ wrote:
Why not look into superflex arms from superior. Easiest way for front end flex.

has any one seen them work? i cant really work out how there bolt up? do they bolt to both the origanal radius arm bolt holes or just one? if it was just one would in not just put as much spress on the one bolt as removing a bolt from a stock setup then!!!

Yep, I have seen them in person. They do flex better than standard arms but still bind on the bushes. Oh yeah I out flexed it by taking the bolt out.

I wouldn't waste my money, besides that they're not legal anyway.

yeah i was just looking into them then, me removing one bolt seems to flex alot more than what i can see in the pics, but there arms should be more stable, better for all around drivin, i think i would rather just keep removing one bolt in the bush or make up a X link and running lock pins in it.

is it too late to say flex is overrated?