They never told me squat about mine when it failed, just that they had to ship it off to Ford.
I wondered the same thing, I don’t see how there’s any way over filling a differential could cause damage. Maybe blown seals because of thermal expansion, then loss of lubrication? But that doesn’t jive if they are vented.
Hold my beer!
Sorry to hear that, but at least it was diagnosed before it left you stranded on the trail. Sixty thousand miles before the first major issue isn't too bad, although a front diff definitely isn't something you'd expect to replace. Hopefully the new unit arrives as promised and solves it for good. I'd be interested to hear if anyone who's had theirs replaced has put a lot of miles on the replacement without any recurring issues.
I have not put a lot, the 10k I have put, have had some very hard duty miles.
Was replaced in less than a week. Has worked perfectly since. Almost 10k so far with about 300 on sand and trails. Agree that front diff going bad is odd, especially since mine is open, just rear locker.
In my decades of experience with differentials (mostly rear), the lube level needs to be far off (low) to grenade the gears if it's a quality setup, and slightly overfilling will not cause that. Given the seemingly-high number of these Bronco diffs failing, it seems this setup has issues that go beyond fluid levels.
