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So...looking at those pics has left me a liittle concerned. Is this to be expected of the OEM u-joints...because they're not greaseable? When the joint goes, will the outer shaft likely fail (like this) as well? I was gonna replace the factory u-joints eventually, but this pic makes me wanna replace the axle shafts as well...and SOONER than LATER. If someone could answer these questions, it would be GREATLY appreciated. Also...I'm wonderin how much mileage this jeep had when this happened?
 

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So...looking at those pics has left me a liittle concerned. Is this to be expected of the OEM u-joints...because they're not greaseable? When the joint goes, will the outer shaft likely fail (like this) as well? I was gonna replace the factory u-joints eventually, but this pic makes me wanna replace the axle shafts as well...and SOONER than LATER. If someone could answer these questions, it would be GREATLY appreciated. Also...I'm wonderin how much mileage this jeep had when this happened?
Every one that I have seen break has broken the ears on the outer shaft...just like the one in that post. Now granted, that makes 6 now that I have seen so it's not that many, but it's a trend I think.
 

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The Jeep has not been wheeled too hard and is running 35's on a d30. I think he said he is around 30k miles.

I forgot to look for the two other caps as he realized the ujoint broke within feet of where it happened. I originally thought maybe one of the caps had come off but surprisingly there was no marks on anything else. He caught it before the joint exploded, just the ears on the outside broke. We were unable to detirmine what the cause was.

I think broken u-joints is something to be expected and would only hit trails prepared for it. In my opinion it is a crucial weak link, something to break before other damgage.

I would say it has nothing to do with them not being greasable, especially this early.

I would recomend tacking the caps on, inspecting them reguarly and bringing a spare set of shafts when on the trail. Today this happened on basically flat ground going around a corner with open diffs. Just proves you never know when it will happen!!
 

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Just to add. The only thing that was broken was the ears on the outer shaft and the caps (obviously) for the broken side were missing. otherwise there was no other failers

 

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Discussion Starter #6
The Superior and Alloy shafts that ive seen do not appear to include ujoints...just the inner/ outer shafts. Is this correct? if so does anyone know what size ujoints are used...260x, 760x? Its hard to accept that this type of failure may happen while wheelin down fire roads...or worse, on the hwy...since (without left/ right spares) one would certainly be SOL and in need of a tow...
 

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Discussion Starter #7
THANK YOU GUYS a million for going over all of this. I'm not a metal guru, but the ears look like the metal was crystalized (maybe not the correct term), but "stressed" to the point of emminent failure...surely this wasnt due to the 4:88s...(?)
 

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something is screwed up here...it seems my REPLY posted- out of sequence (last reply shouldve been #9 but went to #7 spot)...whatever...
 

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Discussion Starter #9
something is screwed up here...it seems my REPLY posted- out of sequence (last reply shouldve been #9 but went to #7 spot)...whatever...Also says "post is a duplicate"...posted in last 5 mins...This is startin to SUCK...
 

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yah, I wish we took the time to look around the area to se if those other caps were there. May have been a clue. Although I really think that if a cap walked out there would have been some marks on something.

ehh, we will never know, just a broken u-joint. Glad we got it done so quick. I was worried it wouldn't work when it went so quick. I don't think that took much longer then changing a damn tire!!!

First thing tomorrow I am buying a 35mm socket and putting my 12 point sockets back into my trail bag :smokin::laughing:
I think K-bear and I can get that socket for you,don't worry about it.
The reason I was asking about the disco was in the other thread in one of the pics it shows the disco still connected

and i am not hungover,

jealous much K-beer?
 

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I think K-bear and I can get that socket for you,don't worry about it.
The reason I was asking about the disco was in the other thread in one of the pics it shows the disco still connected

and i am not hungover,

jealous much K-beer?
We reconnected the discos to help lift the tire. We were in possibly the worst spot to remove the front left tire. Downhill and tilted left. The Hi-Lift was pretty much maxed out to get it up and off. Didn't really want to move it and cause more damage than we had to. After we got the tire off, we dropped it down onto the factory jack so the widow-maker wouldn't have a chance to kill us.
 

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cant imagine that buying spare left/right shafts at the dealership will be cheap!+ they are obviously not up to the task of going offroad...only 6k miles? that aint reassuring. So, again...any idea...size of the joints? Available from Superior or Alloy USA as complete kits (including ujoints)? Also...wondering if the outers and the ujoints are the same size w/ the D30 as the D44 (Rubicon model)?
I'm going to see one of my buddies tomorrow who runs a repair shop and am bringing the broken parts with me. He can probably give me details on the joints, and possibly give me input on to what "might" have caused the failure. I'll let you guys know what he has to say about it.
 

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To be correct, the jeep has 6k miles on it. I'm completely baffled as to what caused it to happen. Like WTF said, it hasn't been wheeled hard (Spring Creek, a few Moab trails, and this trip).

To walk you through it, we wheeled to the top of Twin Cones, no problems at all. On the way down, had it in 4low, 1st gear most of the way (Manual tranny, 4.88 gears). I was letting the engine do the holding back most of the way, assisting with brakes when there was a drop.

We we're at the last switchback to flat road when I dropped off probably a 8" tall rock coming around a corner. I had it turned close to all the way left to make the switchback. I heard a pop, and turned back to WTF to ask him if he heard anything, he said no, so I went about a foot forward. That was when it was clear that it was metal on metal, so I shut it down and found the carnage.

I'd like to figure out the true origins of what caused this, but can only speculate right now as to the cause. I'll go lay out the shaft and get some good pics and post them up. Maybe somebody can come up with a good guess.
 

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yah, I wish we took the time to look around the area to se if those other caps were there. May have been a clue. Although I really think that if a cap walked out there would have been some marks on something.

ehh, we will never know, just a broken u-joint. Glad we got it done so quick. I was worried it wouldn't work when it went so quick. I don't think that took much longer then changing a damn tire!!!

First thing tomorrow I am buying a 35mm socket and putting my 12 point sockets back into my trail bag :smokin::laughing:
 

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Discussion Starter #18
cant imagine that buying spare left/right shafts at the dealership will be cheap!+ they are obviously not up to the task of going offroad...only 6k miles? that aint reassuring. So, again...any idea...size of the joints? Available from Superior or Alloy USA as complete kits (including ujoints)? Also...wondering if the outers and the ujoints are the same size w/ the D30 as the D44 (Rubicon model)?
 

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I would bet that a cap backed out and caused the failure. There isn't much clearance between the caps and the inside of the knuckles, and when they make contact...

This is not just a JK thing. Dana 44's are notorious for it. That is why so many people tack weld the caps. The alloy replacement shafts are machined to accept full circle clips that are less likely to fail and allow the cap to back out. I had a high pinion 44 in the front of my TJ that did the same thing. The Yukon alloy shafts and super joints fixed the problem.
 

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I had it turned close to all the way left to make the switchback. I heard a pop,
99% of the breakages i have seen have happened when the wheels are turned like this. You put a lot of stress on the joint when turned and putting poser to it.
 
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