I have stripped the ring gear on two front diffs now. I hadnt heard of anyone else having this issue, but wanted to double check. I have the stock differential, unlocked. 2002 4Runner with 33" tires.

Both times I was in a similar situation. The front suspension was fully extended as the truck was high centered. I couldnt get traction, so was modulating the brakes a small amount to try and provide power transfer to the other wheel. Most likely in reverse both times. Both times was in the winter, at about 10-15 degree air temp. The truck was warmed up both times, but chances are the diff could have been very cold, being trapped in snow. Both times, I didnt feel any pop or any immediate indication that it was broken. It was only noticeable when on the gas, trying to get out. A loud clicking comes from the front end as the gears skip teeth.

Obviously, I wont be doing this any more, but I find it strange that Ive broken the diff twice in this manner, given the extreme terrain that it handles in the summer.