JK Axle *TUBE* Failures?

[R_Lefebvre]

I'm starting see some talk on some of the Jeep boards that the new JK's seem to have either a design flaw or manufacturing defect where the axle tube, not the shaft, shears right off. A somewhat brittle fracture.

Are you guys aware of this? Could be pretty bad news if you're far from home.

I was an engineer at Dana a few years ago, doing underhood plumbing for a small division of the company. We had a number of cases of really MMMMty tube coming out of the mills causing weird failures. It seemed to us like part of the problem was that during the "steel crisis" (100% fabricated because of US protectionist measures) the steel mills felt they could ship anything they wanted because we were lucky to get steel at all. Also partly because DCX's steel specifications we were using were somewhat lacking.

Anyway, I wonder if this is related, or a design issue. I've never before heard of an axle tube breaking, ever.

Making it worse is the fact that the Jeep dealer is denying the warranty claim.

[Exrunner]

I wonder if its caused by a lot of torque on the axle. I have heard a lot about Ford 8.8's (a common rear axle swap for Jeepers) axle tubes actually spinning in the differential if too much torque is applied to it. A lot of guys weld up trusses and call it a day. Maybe with power and numerical gearing increases, the JK axles should be trussed. Which axle is it? D44, D30 or what?

[R_Lefebvre]

I think it's a D44? This was on a newer Rubi. AFAIK, it was mostly stock. They are denying the claim because it happened off road, not because of mods. So much for "trail rated".

And he's not the only one apparently. I'm seeing this on JK-Forum, this case in particular in the Central Canada forum, but there are links to others.

[I Leak Oil]

Don't know about breaking the axle tubes but I believe bending the inner knuckle is a common problem with the new JK. Is that what you're refering too?
Jason T.

[roadkill]

one of the offroad mags did a write up on this issue, more so bending than the out right breaking of the tube although I've seen reports of both. the fix is either a new axle housing or the use of an internal sleeve and bracing on the "C's" before the axle has a chance to get bent. so far this issue (tube bending and/or breaking) seems to be isolated to the JK axles and not the TJ's

[Totenkopf]

I've been running 35s on mine since I got it, and it has been fine. I think if you jump most stock axles, they will bend.

http://homepage.mac.com/pequine/.cv/pequine/Sites/.Pictures/newJK002.JPG-thumb_140_105.jpg

[roadkill]

anything can be bent but I've heard of more bent/broken JK housings than any other housing

http://www.jk-forum.com/showthread.php?t=73797
http://www.project-jk.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=35942

http://www.project-jk.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=36857

[I Leak Oil]

Ouch! That's definitely broken and certainly not the knuckle issue! How badly do you have to romp on the truck to do that?
Jason T.

[Backwoods Rambler]

I've heard of this problem as well, which is bad because I'm not in the market for a JK and I don't research them; I simply stumbled across the information.

I believe there is a company making weld on sleeving kits to reinforce the axle tubes from bending and breaking. I don't recall a name or where I read this though.

[Photog]

That photograph shows a torsional break. Spiral shape. If there are heim joints on both ends of all those control arms, that could cause the problem.

When the suspension cycles through its full range, the axle will often rotate a little, because the upper control arms are shorter than the lowers. This is not a problem, when the whole axle moves up or down. The problem starts when, one side is up & the other is down. Now the control arms are fighting to rotate each end of the axle in opposite directions.

The bushings in the control arms will absorb this change in rotation, and there is no problem. Even a bushing in one end anda heim at the other is OK. Maybe even a bushin at one end of only the uppers would work. The fewer bushings, the higher the stress. But; if there are heims in both ends of all control arms, there is probably going to be trouble. Not to mention restricted articulation (until it breaks).

[alosix]

That photograph shows a torsional break. Spiral shape. If there are heim joints on both ends of all those control arms, that could cause the problem.

When the suspension cycles through its full range, the axle will often rotate a little, because the upper control arms are shorter than the lowers. This is not a problem, when the whole axle moves up or down. The problem starts when, one side is up & the other is down. Now the control arms are fighting to rotate each end of the axle in opposite directions.

The bushings in the control arms will absorb this change in rotation, and there is no problem. Even a bushing in one end anda heim at the other is OK. Maybe even a bushin at one end of only the uppers would work. The fewer bushings, the higher the stress. But; if there are heims in both ends of all control arms, there is probably going to be trouble. Not to mention restricted articulation (until it breaks).


Those look like rubicon express arms, which typically have a johnny joint and a bushing joint on each arm. This seems really unusual, TJ fronts have been run with radius arms tied in solid (lots of torsion forces) and I've never seen anything like that.

Normally, even if it was too much torsional force, I would expect some of the tiny 1/8 and 3/16 steel mounting points to give way first.

Edit.. looked closer. Def not RE arms on that JK in the pics.. prob full traction then, I'd have to figure that out. Still though.. insane for that to happen.

Jason

[Backwoods Rambler]

...... even if it was too much torsional force, I would expect some of the tiny 1/8 and 3/16 steel mounting points to give way first.......Jason


Agree'd

[Exrunner]

That photograph shows a torsional break. Spiral shape. If there are heim joints on both ends of all those control arms, that could cause the problem.

When the suspension cycles through its full range, the axle will often rotate a little, because the upper control arms are shorter than the lowers. This is not a problem, when the whole axle moves up or down. The problem starts when, one side is up & the other is down. Now the control arms are fighting to rotate each end of the axle in opposite directions.

The bushings in the control arms will absorb this change in rotation, and there is no problem. Even a bushing in one end anda heim at the other is OK. Maybe even a bushin at one end of only the uppers would work. The fewer bushings, the higher the stress. But; if there are heims in both ends of all control arms, there is probably going to be trouble. Not to mention restricted articulation (until it breaks).

This is what I have always thought about when it comes to coil sprung front suspensions and long arm lifts. I know that there are long arm lifts that totally get rid of the separate upper arms, and have long lower arms with small uppers extending off of them. Here is a link to a kit that makes a 3-link suspension for the front of an XJ. Notice the Y-shape link. I know there are kits that have two of these (4-links) arms. Once one side of the axle goes up, and the other down, during full articualtion, the side that goes up will rotate the axle towards the rear of the vehicle....the side that droops will rotate the axle away from the rear of the axle. In other words, if you are looking at the axle from the driver's side, and the passenger side is fully stuffed, while the drivers side is fully drooped, then the long arms will be rotating each end of a solid axle housing in opposite directions....HOW DOES THIS WORK?!?!?! How does it not snap or bend more axle housings??

[chuck45]

I've heard of this problem as well, which is bad because I'm not in the market for a JK and I don't research them; I simply stumbled across the information.

I believe there is a company making weld on sleeving kits to reinforce the axle tubes from bending and breaking. I don't recall a name or where I read this though.

As I have a JK I've been following this issue. It seems that it may be a bad maerial issue as it seems to have happened to early 07 JK's.

The company making the sleeves is Mount Logan Offroad in Logan Utah:
http://www.mtloganoffroad.com/
Their website is lousy and has no info on it to speak of so it's best to talk to them. The cost of the sleeve kit is 125.00 and requires drilling and welding to install. I understand it's about half a days work to install. They charge 150.00 or so to install them. Apparently the hardest thing is drilling the needed 1/2 holes in the axle. Then the sleeves are tapped in and the holes are "plug welded".

I'd like to know how many axles have had this happen. Given the way info travels on the internet it could be a small number and we have to wonder what lead up to it. A problem that seems more common is bending the outer C's and screwing up your camber. This seems to happen with 35" and larger tires. Off Road Evolution sells a gusset kit for 90.00 that seems to take care of the problem. It also requires welding. I've got them on my JK.

[Hilldweller]

The bent C's and trackbar mounts breaking are the most common issues right now.
It's a good thing to watch though.

[chuck45]

The bent C's and trackbar mounts breaking are the most common issues right now.
It's a good thing to watch though.

That's what I've been noticing too. The ORE gusset kit seems to take care of the C issue. Mt Logan also offers a weld on gusset but it seems to have less coverage than the ORE ones.

Trackbar mounts are a bit problematical. They seem ok if the JK is left stock but with any extention upward (to correct bump-stear issues) they are stressed and break unless braced. Rock Krawler makes a 20.00 two piece gusset kit that supposedly braces it and eliminates problems. I've bought it but haven't got around to installing it yet. JKS makes a real substantial kit that reinforces it, braces the passenger side upper control arm mount and provides the option of a high and low (std) track bar pivot position.

[R_Lefebvre]

As I posted in one of the threads, I wasn an engineer at Dana a few years ago. I was doing underhood plumbing not axles, but we had a problem with bad batches of steel tubing coming out of the mills. The macroscopic carbon concentration was ok, but you would have large microscopic pure carbon inclusions that were making what is supposed to be a ductile low-carbon steel actually be brittle. That's kinda what this looks like to me.

As for all the discussion of the way the axle flexes... what kind of suspension is it? 4 bar or 3 bar? 3 bars have no geometric problems, but 4 bars do have bind designed in. The 80's - 90's Mustangs had a 4 link called "Quadra Link" which we called Quadra Bind. It's what made those cars handle so bad. There's a geometric problem, which can only be compensated by large rubber bushings.

My Rover has no upper arms, just semi-rigid lower arms which definitely twist the housing when it articulates. I say semi-rigid, because the arms aren't welded to the housing, but mounted with large bushings.

[Zeero]

I know of two people in the JK's this has happened to, but they were not D44's, they were the D30's that broke on two separate occasions with different Jeeps....one was an X model, the other a Sahara.

[Exrunner]

As I posted in one of the threads, I wasn an engineer at Dana a few years ago. I was doing underhood plumbing not axles, but we had a problem with bad batches of steel tubing coming out of the mills. The macroscopic carbon concentration was ok, but you would have large microscopic pure carbon inclusions that were making what is supposed to be a ductile low-carbon steel actually be brittle. That's kinda what this looks like to me.

As for all the discussion of the way the axle flexes... what kind of suspension is it? 4 bar or 3 bar? 3 bars have no geometric problems, but 4 bars do have bind designed in. The 80's - 90's Mustangs had a 4 link called "Quadra Link" which we called Quadra Bind. It's what made those cars handle so bad. There's a geometric problem, which can only be compensated by large rubber bushings.

My Rover has no upper arms, just semi-rigid lower arms which definitely twist the housing when it articulates. I say semi-rigid, because the arms aren't welded to the housing, but mounted with large bushings.


Thanks...thats what I was looking for. Bushings are the saving grace for those then. I was thinking more about a 4-link.

[Root Moose]

It's a materials problem that was supposedly corrected during the `07 model year run. Both Dana 44s and Dana 30s are affected. The failures happen on both street trucks and wheeling trucks.

One of the guys I know was on an EOTB run a few weeks ago and a JK had this happen to it. Sure enough, MY07.

[chuck45]

As I posted in one of the threads, I wasn an engineer at Dana a few years ago. I was doing underhood plumbing not axles, but we had a problem with bad batches of steel tubing coming out of the mills. The macroscopic carbon concentration was ok, but you would have large microscopic pure carbon inclusions that were making what is supposed to be a ductile low-carbon steel actually be brittle. That's kinda what this looks like to me.

As for all the discussion of the way the axle flexes... what kind of suspension is it? 4 bar or 3 bar? 3 bars have no geometric problems, but 4 bars do have bind designed in. The 80's - 90's Mustangs had a 4 link called "Quadra Link" which we called Quadra Bind. It's what made those cars handle so bad. There's a geometric problem, which can only be compensated by large rubber bushings.

My Rover has no upper arms, just semi-rigid lower arms which definitely twist the housing when it articulates. I say semi-rigid, because the arms aren't welded to the housing, but mounted with large bushings.

I think a lot of failures we see today are due to poor materials. I was recently on a job where we had a 40 ft piece of 7" pipe split at it's seem for 35 ft of it's length; at a fraction of it's rated burst pressure. Most pipe has a seem; you just can't see it (nobody wants to pay for seamless). The pipe had been sourced in China. The Asian pipe we're working with today is thought of as junk and doesn't hold up.

So I'm curious, do you know where the tubes in the axles that failed came from? Was it domestic or foreign? How does something like this slip past QC?

As to the issue of 3 and 4 link and bushings - how do arms that have johnny joints or superflex joints compare to bushings? From what I can see there is more articulation with the flex type joints. I know on my setup I have a bushing at one end of a control arm and a flex joint in the other. For instance the front uppers have a bushing at the axle and the lowers have the bushing at the frame.

[R_Lefebvre]

So I'm curious, do you know where the tubes in the axles that failed came from? Was it domestic or foreign? How does something like this slip past QC?


I don't know where the axles came from, but the tubing I had problems with came from the good ole' USofA. Anybody is capable of producing junk.

How does it get past Q&A? I can't speak with authority on axles, but *generally* in the auto industry... there is NONE. Well, at least not what you'd think. All the "torture testing" happens before a vehicle launch. After launch, there really isnt much materials testing going on. As long as the parts fit the jig after welding, they're good to go. The Tier 1 supplier relies on the steel supplier to self-certify the material. Fox watching the hen house.