Here's a video of me on the trail where the axle broke. I've only driven across that pond the one time that it was filmed and felt real nervous because of my tires. At one point, you hear a discussion between myself and my roommate where I was nervous about going down a hill "You don't want to go down it? Then don't go down it." There was nothing in my driving the day that axle broke that differs from what's in this video. It was my first hill climb that I attempted that day that the axle broke. In the video, it's the hill that I climb the last two times. The axle broke at the very point where you see the driver's side wheel spinning. Also, notice the audible drivetrain backlash going into the pond. I sent it in to the dealership regarding the backlash last month and they said that was normal.

http://youtube.com/watch?v=Cvn13MKSc6E

 

Nothing in your driving???? 2500-300 rpm's in 4lo 1st gear is a lot of rpm's. You problably had lots of whell spin and then you got traction, perfect recipe for disaster.

 

Perhaps I had wheelspin and ESP locked down the brake.

 

I didn't think ESP engaged in 4-Lo.... What is brake lock traction control? Is that ESP?

 

That's what I meant. Brake-lock traction control locks down the brake on a spinning wheel (poor man's locker). I've seen a lot of people refer to it as ESP, which may be a misnomer. According to the manual, you can't turn this off.

 

Yeah, that's not ESP, ESP turns off in 4L if I'm not mistaken.

 

The way I read it --

ESP is automatically "off" in 4-lo unless your vehicle speed exceeds 40mph... TCS (traction control system) in 4-lo is automatically off irregardless of vehicle speed and remains off while engaged in 4-lo...

 

Well, mine just broke. I was off-road in some sand dunes, attempting to get up a very mild hill. I was in 4-lo, and i heard BANG, followed by clunk clunk clunk... I let it roll back down the hill, and looked in the sand. I didnt see anything visible so I drove out to the pavement, probably about 1 minute away. When i get out, I clearly see the U-joint had a catostrophic (sp) failure. It completely ripped apart, and took part of the axle shaft that connects to it. I used chysler's roadside assistance and within 45 minutes they towed my jeep in. Met with the jeep dealer and told them I was on a dirt road in 4WD and it broke. They didnt question it and the parts have already been ordered. I should get it back sometime next week.

edit: My 4 dr JK X, was built in 02/07. It has 2500 miles on it.

 

I'm not sure if they were that high, but even if they were at 3000 RPM, considering I have a 4.10 axle ratio, that would put me w/ a 50:1 overall ratio. At 3000 / 50 puts me at exactly 60 RPM, or 1 revolution per second (perhaps 2 if one wheel is spinning, but w/ the traction control, I doubt it would hit that). Just in visualizing 1 revolution per second (computes to 5 mph) on loose dirt doesn't give me the impression of excessive wheel spin.

 

Sorry, but I don't see or hear any indication of an axle/u-joint breaking in that video. The backlash is normal and existed in previous models so it's completely unrelated an not to blame. Have you ever heard a u-joint snap? It's not something you would wonder about and have to analyze to figure when it happened. It sounds like a gun shot really and would have been very audible in that video. If I was your dealer I'd be suspicious of your story - just does not seem plausible given the way you were driving in the video.