Re longarms with passenger upper removed

zachandandy · Feb 10, 2011

I've searched and searched, and it seems like everyone talks about removing 1 of the uppers, but then they get talked out of it. Anyone actually do it? The reasons for not doing it make no sense to me. People refer to having only 1 bolt holding the axle, isn't there only 1 at the frame side regardless? Leafs locate and support the vehicle off 1 bolt at each end. Removing 1 upper makes the re almost identical to the iro kit doesn't it? I think I've talked myself into it, but I'd still like to hear from others who have done it.

DeftwillP · Feb 10, 2011

Look under your jeep and compare the size of the bolts you're talking about. It'll make sense why you shouldn't run one upper when you that bolt compared to the ones that hold lowers, leafs, etc

Tapatalky

zachandandy · Feb 10, 2011

The larger bolts are under more stress as they locate the axle, the upper is under rotational load only. I have no experience with the IRO kit, but their y-link looks like 1 radius arm and 1 lower link only. Do they use a larger bolt?

rockclimber · Feb 10, 2011

bad idea.

the driver side UCA mount is not strong enough on its own to prevent the axle from rotating on its axis in an extreme situation such as an accident, or any number of situations offroad.

on top of that you only have 1 10mm bolt holding your pinion angle.

the next problem you will run into is ripping off the lower control arm mounts because they will be taking the full force of the axle as it travels.

there is no need to remove the upper CA in a radius style setup. the IRO kit is not a 3 link, its is a radius arm with a track-bar; missing an upper link, and a crappy one at that.

it does not flex any more than a traditional radius arm setup. if the upper and lower super flex joints on the passenger side are aligned the same at full bump then the axle will be free to rotate to the full potential of the shocks and springs.

zachandandy · Feb 10, 2011

I was able to find the answer to the last question. http://www.ironrockoffroad.com/Merchant2/XJ long arm upgrade install.pdf Note item # 20 of IRO instructions, install supplied 10x90 mm bolt in upper y-link. From what I've seen guys are beating and flexing the **** out of jeeps with IRO kits and they hold up just fine. I'll report back with my results upon removal of my passenger side upper.

rockclimber · Feb 10, 2011

its your funeral.

zachandandy · Feb 10, 2011

The binding of a radius arm suspension is huge. When 1 end of the axle is pushed up, the arm on that side flattens out and forces the pinion down. When the other side tries to droop at the same time, the angle of the arm increases, rotating the pinion up. Trying to twist a solid axle in opposite directions will obviously result in binding, basic physics.

ktm racer 419 · Feb 10, 2011

zachandandy said:
From what I've seen guys are beating and flexing the **** out of jeeps with IRO kits and they hold up just fine. I'll report back with my results upon removal of my passenger side upper.

i have never personally seen anyone wheeling an iro setup "hard"

and nobody i wheel with would run that setup because a single 10mm bolt keeping your axle from flopping around doesnt sit well with any of us

rockclimber · Feb 10, 2011

first: the upper does see more force than rotational. one 10mm bolt will not be sufficient to hold the axle in place. think about it: you are cutting the strength of your upper CA in half by doing this.

the next problem is the UCA mount itself, its not strong enough to be handle all the forces of axle rotation and suspension load on its own.

it will probably fine for driving around town and very light wheeling; but if you really need to increase your flex to the absolute maximum of that radius style setup (a point which is most likely beyond your springs, shocks, brake lines, LCA brackets, and driveshaft) the forces you are going to be creating are more than enough to snap that 10mm bolt.

and if you get into an accident of any kind your going to end up with that D30 sitting in your lap.

rockclimber · Feb 10, 2011

double.

srimes · Feb 10, 2011

Has anyone even heard of the IRO bolt breaking? I agree that that bold _sounds_ weak, but people run it and if it was that bad we'd hear about it failing at some point

grandrunner seemed to like his:
http://www.naxja.org/forum/showthread.php?t=1025839

and only switched because it wouldn't fit with the new axle truss.

It does seem like you could put a bigger bolt in there. As a 3-link there should be less twisting stress on that busing so I'd think that an oversized bolt would work. But that's just a guess.

kastein · Feb 10, 2011

great another IRO pissing fight...

Dunno if I'd run a radius arm with only one upper on a stock sized bolt, but at least you're keeping the driver side upper portion, which is stronger than the passenger upper bracket on stock non-disconnect axles.

rockclimber · Feb 10, 2011

kastein said:
great another IRO pissing fight...

Dunno if I'd run a radius arm with only one upper on a stock sized bolt, but at least you're keeping the driver side upper portion, which is stronger than the passenger upper bracket on stock non-disconnect axles.

this isn't a pissing fight over IRO...thats been done.

this is a guy who thinks what he has is a good idea; turns out it isn't. And regardless of the fact that he posted a thread asking for advice he is going against all of that advice and doing what he wants to do anyways.

Oil Town XJ · Feb 10, 2011

Its not worth the extra 50 you might add to your ramp score! Safety>flex

1990JEEPXJ · Feb 10, 2011

rockclimber said:
the next problem is the UCA mount itself, its not strong enough to be handle all the forces of axle rotation and suspension load on its own.

so the cast mount on top of the diff housing isnt strong enough?

rockclimber · Feb 10, 2011

1990JEEPXJ said:
so the cast mount on top of the diff housing isnt strong enough?

not on its own...

it will handle the stress fine in a normal situation, but when the S.H.T.F. its going to get cracked or worse ripped off...

there is a reason that everyone who makes a real 3 link kit uses a bridge over the diff that ties that bracket to each tube. in fact most of them have you cut that thing off and have the bracket on the bridge itself.

there are pics somewhere on JF of the stock diff side bracket cracked from it not being reinforced and used as a 3link...

I've been looking around for them, but I can't remember what thread they are in.

kastein · Feb 10, 2011

rockclimber said:
not on its own...

it will handle the stress fine in a normal situation, but when the S.H.T.F. its going to get cracked or worse ripped off...

there is a reason that everyone who makes a real 3 link kit uses a bridge over the diff that ties that bracket to each tube. in fact most of them have you cut that thing off and have the bracket on the bridge itself.

there are pics somewhere on JF of the stock diff side bracket cracked from it not being reinforced and used as a 3link...

I've been looking around for them, but I can't remember what thread they are in.

I'm reasonably certain you are wrong here, for all but the most severe abuse (jeepspeed, etc.) That cast-in mount is pretty damn strong.

The reason most 3 link kits have you cut it off is so you can use a proper heim joint (or similar) instead of a pressed in bushing.

rockclimber · Feb 10, 2011

kastein said:
I'm reasonably certain you are wrong here, for all but the most severe abuse (jeepspeed, etc.) That cast-in mount is pretty damn strong.

The reason most 3 link kits have you cut it off is so you can use a proper heim joint (or similar) instead of a pressed in bushing.

those are the situations I'm talking about; a freeway collision, a serious rollover, hell hitting a hidden boulder while going fast, etc.

all situations that are well within the realm of possibility if the OP is really needing that extra 2" of flex.

oh and you don't need to run a bridge to run a flex joint

ktm racer 419 · Feb 10, 2011

i have never seen an out of the box radius arm flex to its limits due to the control arms binding (just that old ford junk)

its always limit straps or shocks.

taking an upper out for more flex is a retarded argument anyway.

rockclimber · Feb 10, 2011

ktm racer 419 said:
i have never seen an out of the box radius arm flex to its limits due to the control arms binding (just that old ford junk)

its always limit straps or shocks.

taking an upper out for more flex is a retarded argument anyway.

:wave1:

Re longarms with passenger upper removed

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