Just out of interest, my brother was cleaning the chassis for me yesterday :-) and he noticed a tag attached to the BTR diff with JJ stamped on it, Is the tag saying anything?
Aimy, very interesting. Doesn't look like am original tag, however. I guess Thomas might be right: Sign of a rebuilt diff. But no idea what "JJ" might mean. Sorry.
Just found this topic while researching diffs. My Tamora also has a JJ tag, on a 3.73 diff. It's never been out of the car, as far as I know, and I've owned it for most of its life.