Iron rock offroad long arm upgrade

[ktm racer 419]

The best part of all these threads is the fact that the stock trackbar bolt is a 10mm. Wow now there's millions of jeeps driving around with 1 10mm bolt holding the axle in place and yet no dead kittens? As you progress towards more difficult wheeling, you upgrade that bolt, yet you act like that's not an option with the IRO kit? Drill out the bushing? Buy the press in Johnny joint that accepts a 9/16" bolt and drill out the caster adjuster thing?

Ive broken a handful of those on the trackbar, not a good feeling. Luckily i caught it before the entire bolt fell out.

Anywho, take a look at the iro caster adjuster. Where that bolt goes through is a big slot. You will have to grind away at that slot and then at that point i'm sure the integrity of the bracket is compromised. Its really too bad they don't come up with a beefed up bracket with provisions for a larger bolt and a drop in cartridge joint.

 

[clean4drxj]

Finally found a thread that made you feel all warm and fuzzy inside talkin about that spiffy 3" lift.


Daddy's proud

EDIT::yelclap::sad1arty1:


:dunno:

I just dont understand why you have such a hardon for IRO.. They make a couple of good things but longarms isn't one of them, PREACH ON INTERNET WISORD!

 

[MaxxXJ]

Random thought... What holds the track bar in place on the axle side "Stock"?

A single 10mm bolt? What holds a 12,000 lb winch in place? 3/8 bolts
I bet the braking force on those calipers is pretty severe... Those are like 10mm bolts too right? for crying out loud it's 4- 1/4" bolts that hold the driveline in place at the u joints and those get abused on every trip out when you use them as a rock slider! ...

Ok so here's what I've gathered over the 4 pages of crap, no one likes the camber adjuster thing, no one is comfortable with a single 10mm bolt holding it together...

I bet If IRO remade their radius arms to be ajustable by threads like most of the adj short arms and make them to where they were more likely to fit multiple axle applications.. And possibly made it to where both lower arms had adjustable uppers... They would be perfectly fine with the kit... To add to this, no one likes it because its just 1 10mm bolt... If it came loose, fell out etc there isn't a second one to keep your equipment from self destructing...

Aside from Being counter helpful... Why not give him an option to another kit with a link and a price and let him decide for himself? You've made it clear IRO sucks... Now point him at another reasonable option... This is like someone bashing someone in a FS thread about how it is priced too high...

 

[kastein]

At least the u joint guy said he would give $500 lol.

he never gave me shit

The best part of all these threads is the fact that the stock trackbar bolt is a 10mm. Wow now there's millions of jeeps driving around with 1 10mm bolt holding the axle in place and yet no dead kittens? As you progress towards more difficult wheeling, you upgrade that bolt, yet you act like that's not an option with the IRO kit? Drill out the bushing? Buy the press in Johnny joint that accepts a 9/16" bolt and drill out the caster adjuster thing?

maybe you haven't noticed but steering forces are quite different from braking and drive torque at the wheels.

Random thought... What holds the track bar in place on the axle side "Stock"?

A single 10mm bolt?

yes, see above. steering forces are not the same as drive torque + braking forces

What holds a 12,000 lb winch in place? 3/8 bolts

four of them

I bet the braking force on those calipers is pretty severe... Those are like 10mm bolts too right?

umm, go look at your brake system again please. You are wrong. The slide bolts just locate the caliper, the braking force is handled by those two giant cast/forged arms on the steering knuckle that the brake pads ride directly on. Hell I have driven home with only one slide bolt installed without realizing it because the other fell out.

for crying out loud it's 4- 1/4" bolts that hold the driveline in place at the u joints and those get abused on every trip out when you use them as a rock slider! ...

Wrong again... the actual torque is handled by the sides of the yoke, the 1/4-28 bolts you're talking about just hold the ujoint caps into the yoke so they don't pop out.

 

[zachandandy]

I'm no engineer, but under hard cornering, I'd have to say there is a lot of force on that trackbar bolt. Especially in a lifted vehicle with a high center of gravity. I think we have all seen more broken tie rod ends than the 1 guy with the broken bolt in this kit. It's not the best design, but it has held up a lot longer than the rough country flex joints that were sloppy after 1 wheeling trip.

 

[kastein]

Are you their PR guy or something? :spin1:

Alright. Time to do some math.

 

[zachandandy]

No, but unlike all you guys who are convinced it doesn't work, I've installed 1. My wife's wj had been through the rubicon, fordyce, and deer valley with that 1 10mm bolt doing its job. The rough country track bar folded on the first trip out. I'd much rather run the IRO kit than anything rough country makes. It's easy to come on and tell everyone it won't work, but I and many others have watched it work for years.

 

[ROBZ95Xj]

No, but unlike all you guys who are convinced it doesn't work, I've installed 1. My wife's wj had been through the rubicon, fordyce, and deer valley with that 1 10mm bolt doing its job. The rough country track bar folded on the first trip out. I'd much rather run the IRO kit than anything rough country makes. It's easy to come on and tell everyone it won't work, but I and many others have watched it work for years.

Jeep takes stock rubicons down them trails, yup there pretty hardcore

 

[kastein]

Force applied to track bar bolt while cornering:

Assume a 1G corner. This is probably ****ing impossible in a cherokee, even a lowered one, hell even a mazdaspeed 3 GT can only pull a 1.3G turn. But still, I'll use a 1G turn as an example.

Even assuming ALL the weight of the jeep, built for offroad, weighing 4000lbs, is on the track bar (when probably only 1/2 to 3/4 of it is even on the front suspension, and much of it is not bearing on the track bar at all) the 10mm track bar bolt will only see a 4000lb shear force. And it's in double shear, so each side of that bolt only sees around 2000lbs of shear force. It's a freakin' ISO PC 10.9 10mm bolt with a shear strength of 51kN (11400lbs force), that is not going to shear with a safety factor of at least 2.5. Maybe if you hit a massive pothole or bounced it off a rock way harder than you should, shock/impact forces are probably the issue here.

Alright. Now assume you're in 1st gear, low range, with an AX15 transmission and 4.56 diff gears. You rev up to 3000rpm and drop the clutch to get over an obstacle.

4.0 torque at 3000rpm = approx. 240 foot pounds
after AX15 1st gear (3.83) = 919 foot pounds
after NP231 low range (2.72) = 2500 foot pounds
after 4.56 axle gears = 11400 foot pounds

Even assuming the UCA mount is one foot tall (hint, it isn't, it's more like 6"-8", meaning you can multiply that applied shear force number by 1.5 to 2), with enough traction (or shock loading, i.e. the torque suddenly being applied and working against the inertia of the stationary axle housing and weight of the tires) you are applying a whole lot of force to that one silly 10mm bolt, approx. 11400lbs shared between the two sides. Sure, this is a napkin calculation, you can say that all you want, but it's a napkin calculation that I didn't even bother to apply the last torque multiplication (the UCA moment arm being less than 1 foot long) to and the applied force ends up around the same number as the shear strength of that damn bolt.

Add in the fact that the UCA mount is a lot less than 12" from the center of the axle tube, AND the fact that some of you probably have better gears than 4.56, rev it up above 3000rpm, and possibly even have an AW4 with a torque converter increasing your torque multiplication, and the nonexistent safety factor becomes even less existent.

Yeah, **** IRO longarms and their stupid single UCA mount 10mm bolt. Redo my math yourself if you want.


Reference materials:
http://www.blacksfasteners.co.nz/assets/BoltShearCapacity_14-15.pdf ISO PC shear forces
http://www.jeep4.0performance.4mg.com/images/Torque.jpg 4.0 torque chart (use bright red line, stock 4.0)

 

[MoparManiac]

You forgot to divide the torque in half coming out of the t-case.

 

[kastein]

that's why I'm not a mechanical engineer.

 

[MoparManiac]

And I'm pretty sure the farther away from axle centerline you go, the LESS torque it will see.

 

[MoparManiac]

And you're also assuming the front tires are completely bound up in that calculation in order to get all 240 ft-lbs from the engine.

I'm no mech engineer either so I could be wrong as well :laugh:

 

[kastein]

And I'm pretty sure the farther away from axle centerline you go, the LESS torque it will see.

Yeah, but I assumed the mount was 1 foot tall (mostly so I could go hurr durr 11400 foot pounds means 11400 pounds force at 1 foot), since it's probably more like 6-8" tall it sees more torque.

 

[zachandandy]

Theoretical math means nothing in the real world. Please bring a stock rubicon up Thompson hill. And nobody said this kit was suitable for running the hammers. As I've said, I've seen parts fail from just about every manufacturer, and yet we have one broken bolt and some math as "proof" this kit doesn't work? You guys with no experience want to come on here with fanboi and pr guy comments and zero experience with the product, did someone from IRO bang your girl or do you just have a hard on for them?

 

[kastein]

ok, since theoretical math means nothing and real world experience and pictures of busted-ass IRO hackjob horseshit mean nothing too, what exactly do you want?

Oh right. You want to hear that IRO is the return of christ and that all shall be saved the second they install the kit. I'm happy for you

 

[ktm racer 419]

Theoretical math means nothing in the real world. Please bring a stock rubicon up Thompson hill. And nobody said this kit was suitable for running the hammers. As I've said, I've seen parts fail from just about every manufacturer, and yet we have one broken bolt and some math as "proof" this kit doesn't work? You guys with no experience want to come on here with fanboi and pr guy comments and zero experience with the product, did someone from IRO bang your girl or do you just have a hard on for them?

so easy a golf cart can do it

http://www.youtube.com/watch?v=IvYVVGFDOFM


never said the kit doesn't work. just pointed out the faults. Anyone with a couple hundred bucks and a welder can throw together some control arms and make them flex.

 

[scottmcneal]

Theoretical math means nothing in the real world. Please bring a stock rubicon up Thompson hill. And nobody said this kit was suitable for running the hammers. As I've said, I've seen parts fail from just about every manufacturer, and yet we have one broken bolt and some math as "proof" this kit doesn't work? You guys with no experience want to come on here with fanboi and pr guy comments and zero experience with the product, did someone from IRO bang your girl or do you just have a hard on for them?

:doh:Ok if you want to be rude do it right.You need to use smiley faces dammit.This way nobody gets butthurt.

See that looks so much nicer.:looser:

 

[ibjeepin95]

Finally found a thread that made you feel all warm and fuzzy inside talkin about that spiffy 3" lift.


Daddy's proud

EDIT::yelclap::sad1arty1:


:dunno:

No. If you had half a brain you could figure it out. At 3", your control arm angles aren't bad. What I was saying is that a well set up short arm (upgraded steering, good track bar, shocks set up properly, and control arms with Currie JJ's at each end) is better than that IRO trash. Then again, I'd rather run this setup at any height with drop brackets then this abomination. It would at least give you peace of mind. I mean really, could they not be so damn cheap that they couldn't add another joint on the passenger side lower for the radius arm, ditch the caster adjustment, and use a joint for a bigger bolt? At least you could get an adjustable arm out of it.

Oh, and get off IRO's nut sack. Of course, unless they are paying you to be this much of a fan boy.

 

[zachandandy]

Your worst case scenario math? Remember that the trackbar and even the damn shocks bolt in in a way that fights axle rotation. No I wouldn't rely on them to hold the pinion in place, but some of that torque load is distributed there. My wife, and the average person buying this kit are not running full throttle neutral drop bound up assaults on anything. IT IS AN ENTRY LEVEL KIT. If you drive like your mathematical discription, your stock axles and driveshafts will probably break before that 10mm bolt.