Ed wrote:
Quote:
Forgive my ignorance, but I'm straining my eyes here and really can't see the crack!! Is it that slightly moist spot near where the joint is from where they cast it?
Also, under what conditions did this fail? What size tires, lift, etc? Did you bang the jeep hard off of something?
Also, I'm not seeing how this part could crack. Heat? What would put so much force right there that it would crack? The pinion torquing in it's bearings? Strange.
Here's a broken one.

The pictures at the start of the thread are of an intact diff. Once it's broken it's too late to do anything except replace the whole diff casing. The collar is (possibly) a preventative measure, not a fix.
As posted in the other threads on this subject, it seems that it happens when your wheels are freely spinning and suddenly grip. Like if you get airbourne!
wow, that is an issue!! does it only happen to people who jump their jeeps, or does it happen if you're trying to get up something and have to spin alot of tire to do so??
something fishy is going on with that pinion for sure. the pinion bearings must be wanting to take a hike, and the aluminum is just not strong enough to tell it no. I agree with you guys' theory of why it's happening, but I have an idea to add to it. I wonder if having the diff not so rigidly mounted would help?? Like have it mounted up with really stuff poly bushings, so it was essentially not going much of anywhere, but with a big shock load, it may be able to move. I'm saying this because it seems to me that if the wheels are spinning, and then they catch, the pinion is going to be forced downwards. It seems to me that the diff is mounted very rigidly. If there were just the tiniest bit of give in the mounts, so that under these extreme, yet rare, stresses the whole diff could rotate down slightly, transferring the brunt of the strain to the diff mounting system, rather than exclusively to the pinion bearings.
What do you guys think?